@@ -523,7 +523,7 @@ test_expect_success 'Verify descending sort' '
 
 test_expect_success 'Give help even with invalid sort atoms' '
 	test_expect_code 129 ${git_for_each_ref} --sort=bogus -h >actual 2>&1 &&
-	grep "^usage: ${git_for_each_ref}" actual
+	test_grep "^usage: ${git_for_each_ref}" actual
 '
 
 cat >expected <<\EOF

@@ -622,7 +622,7 @@ test_expect_success 'Quoting style: tcl' '
 for i in "--perl --shell" "-s --python" "--python --tcl" "--tcl --perl"; do
 	test_expect_success "more than one quoting style: $i" "
 		test_must_fail ${git_for_each_ref} $i 2>err &&
-		grep '^error: more than one quoting style' err
+		test_grep '^error: more than one quoting style' err
 	"
 done
 

@@ -1892,7 +1892,7 @@ test_expect_success "${git_for_each_ref} --stdin: fails if extra args" '
 	>in &&
 	test_must_fail ${git_for_each_ref} --format="%(refname)" \
 		--stdin refs/heads/extra <in 2>err &&
-	grep "unknown arguments supplied with --stdin" err
+	test_grep "unknown arguments supplied with --stdin" err
 '
 
 test_expect_success "${git_for_each_ref} --stdin: matches" '

@@ -1955,11 +1955,11 @@ test_expect_success "${git_for_each_ref} with nested tags" '
 
 test_expect_success 'is-base atom with non-commits' '
 	${git_for_each_ref} --format="%(is-base:HEAD) %(refname)" >out 2>err &&
-	grep "(HEAD) refs/heads/main" out &&
+	test_grep "(HEAD) refs/heads/main" out &&
 
 	test_line_count = 2 err &&
-	grep "error: object .* is a commit, not a blob" err &&
-	grep "error: bad tag pointer to" err
+	test_grep "error: object .* is a commit, not a blob" err &&
+	test_grep "error: bad tag pointer to" err
 '
 
 GRADE_FORMAT="%(signature:grade)%0a%(signature:key)%0a%(signature:signer)%0a%(signature:fingerprint)%0a%(signature:primarykeyfingerprint)"

@@ -173,7 +173,7 @@ rev_list_tests_head () {
 
 	test_expect_success "bitmap --objects handles non-commit objects ($state, $branch)" '
 		git rev-list --objects --use-bitmap-index $branch tagged-blob >actual &&
-		grep $blob actual
+		test_grep $blob actual
 	'
 }
 

@@ -242,16 +242,16 @@ basic_bitmap_tests () {
 		GIT_PROGRESS_DELAY=0 \
 			git pack-objects --all --stdout --progress \
 			</dev/null >/dev/null 2>stderr &&
-		grep "Enumerating objects: $count, done" stderr &&
-		grep "pack-reused $count" stderr &&
+		test_grep "Enumerating objects: $count, done" stderr &&
+		test_grep "pack-reused $count" stderr &&
 
 		# now the same but with one non-reused object
 		git commit --allow-empty -m "an extra commit object" &&
 		GIT_PROGRESS_DELAY=0 \
 			git pack-objects --all --stdout --progress \
 			</dev/null >/dev/null 2>stderr &&
-		grep "Enumerating objects: $((count+1)), done" stderr &&
-		grep "pack-reused $count" stderr
+		test_grep "Enumerating objects: $((count+1)), done" stderr &&
+		test_grep "pack-reused $count" stderr
 	'
 }
 

@@ -283,7 +283,7 @@ test_rev_exists () {
 		then
 			test_path_is_file $midx-$(midx_checksum $objdir).rev
 		fi &&
-		grep "\"category\":\"load_midx_revindex\",\"key\":\"source\",\"value\":\"$kind\"" event.trace
+		test_grep "\"category\":\"load_midx_revindex\",\"key\":\"source\",\"value\":\"$kind\"" event.trace
 	'
 }
 

@@ -63,9 +63,9 @@ test_expect_success "connect with $BUNDLE_URI_PROTOCOL:// using protocol v2: no
 		>actual 2>err &&
 
 	# Server responded using protocol v2
-	grep "< version 2" log &&
+	test_grep "< version 2" log &&
 
-	! grep bundle-uri log
+	test_grep ! bundle-uri log
 '
 
 test_expect_success "connect with $BUNDLE_URI_PROTOCOL:// using protocol v2: have bundle-uri" '

@@ -78,10 +78,10 @@ test_expect_success "connect with $BUNDLE_URI_PROTOCOL:// using protocol v2: hav
 		>actual 2>err &&
 
 	# Server responded using protocol v2
-	grep "< version 2" log &&
+	test_grep "< version 2" log &&
 
 	# Server advertised bundle-uri capability
-	grep "< bundle-uri" log
+	test_grep "< bundle-uri" log
 '
 
 test_expect_success "clone with $BUNDLE_URI_PROTOCOL:// using protocol v2: request bundle-uris" '

@@ -95,13 +95,13 @@ test_expect_success "clone with $BUNDLE_URI_PROTOCOL:// using protocol v2: reque
 		>actual 2>err &&
 
 	# Server responded using protocol v2
-	grep "< version 2" log &&
+	test_grep "< version 2" log &&
 
 	# Server advertised bundle-uri capability
-	grep "< bundle-uri" log &&
+	test_grep "< bundle-uri" log &&
 
 	# Client did not issue bundle-uri command
-	! grep "> command=bundle-uri" log &&
+	test_grep ! "> command=bundle-uri" log &&
 
 	GIT_TRACE_PACKET="$PWD/log" \
 	git \

@@ -111,13 +111,13 @@ test_expect_success "clone with $BUNDLE_URI_PROTOCOL:// using protocol v2: reque
 		>actual 2>err &&
 
 	# Server responded using protocol v2
-	grep "< version 2" log &&
+	test_grep "< version 2" log &&
 
 	# Server advertised bundle-uri capability
-	grep "< bundle-uri" log &&
+	test_grep "< bundle-uri" log &&
 
 	# Client issued bundle-uri command
-	grep "> command=bundle-uri" log &&
+	test_grep "> command=bundle-uri" log &&
 
 	GIT_TRACE_PACKET="$PWD/log3" \
 	git \

@@ -128,13 +128,13 @@ test_expect_success "clone with $BUNDLE_URI_PROTOCOL:// using protocol v2: reque
 		>actual 2>err &&
 
 	# Server responded using protocol v2
-	grep "< version 2" log3 &&
+	test_grep "< version 2" log3 &&
 
 	# Server advertised bundle-uri capability
-	grep "< bundle-uri" log3 &&
+	test_grep "< bundle-uri" log3 &&
 
 	# Client did not issue bundle-uri command (--bundle-uri override)
-	! grep "> command=bundle-uri" log3
+	test_grep ! "> command=bundle-uri" log3
 '
 
 # The remaining tests will all assume transfer.bundleURI=true

@@ -275,7 +275,7 @@ test_http_push_nonff () {
 	'
 
 	test_expect_success 'non-fast-forward push show ref status' '
-		grep "^ ! \[rejected\][ ]*$BRANCH -> $BRANCH (non-fast-forward)$" output
+		test_grep "^ ! \[rejected\][ ]*$BRANCH -> $BRANCH (non-fast-forward)$" output
 	'
 
 	test_expect_success 'non-fast-forward push shows help message' '

@@ -195,7 +195,7 @@ test_expect_success 'delete ref while another dangling packed ref' '
 test_expect_success 'pack ref directly below refs/' '
 	git update-ref refs/top HEAD &&
 	git ${pack_refs} --all --prune &&
-	grep refs/top .git/packed-refs &&
+	test_grep refs/top .git/packed-refs &&
 	test_path_is_missing .git/refs/top
 '
 

@@ -19,7 +19,7 @@ test_expect_success '--exists with missing reference' '
 
 test_expect_success '--exists does not use DWIM' '
 	test_expect_code 2 ${git_show_ref_exists} $GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME 2>err &&
-	grep "reference does not exist" err
+	test_grep "reference does not exist" err
 '
 
 test_expect_success '--exists with HEAD' '

@@ -743,7 +743,7 @@ test_expect_success 'subtest: lazy prereqs do not turn off tracing' '
 	test_done
 	EOF
 
-	grep "echo trace" lazy-prereq-and-tracing/err
+	test_grep "echo trace" lazy-prereq-and-tracing/err
 '
 
 test_expect_success 'subtest: tests clean up after themselves' '

@@ -815,7 +815,7 @@ test_expect_success 'subtest: test_atexit is run' '
 
 test_expect_success 'test_oid provides sane info by default' '
 	test_oid zero >actual &&
-	grep "^00*\$" actual &&
+	test_grep "^00*\$" actual &&
 	rawsz="$(test_oid rawsz)" &&
 	hexsz="$(test_oid hexsz)" &&
 	# +1 accounts for the trailing newline

@@ -827,7 +827,7 @@ test_expect_success 'test_oid can look up data for SHA-1' '
 	test_when_finished "test_detect_hash" &&
 	test_set_hash sha1 &&
 	test_oid zero >actual &&
-	grep "^00*\$" actual &&
+	test_grep "^00*\$" actual &&
 	rawsz="$(test_oid rawsz)" &&
 	hexsz="$(test_oid hexsz)" &&
 	test $(wc -c <actual) -eq 41 &&

@@ -839,7 +839,7 @@ test_expect_success 'test_oid can look up data for SHA-256' '
 	test_when_finished "test_detect_hash" &&
 	test_set_hash sha256 &&
 	test_oid zero >actual &&
-	grep "^00*\$" actual &&
+	test_grep "^00*\$" actual &&
 	rawsz="$(test_oid rawsz)" &&
 	hexsz="$(test_oid hexsz)" &&
 	test $(wc -c <actual) -eq 65 &&

@@ -884,11 +884,11 @@ test_expect_success 'test_bool_env' '
 		# test script, hence the redirection of fd 7, and aborts
 		# with "exit 1", hence the subshell.
 		! ( test_bool_env envvar true ) 7>err &&
-		grep "error: test_bool_env requires bool values" err &&
+		test_grep "error: test_bool_env requires bool values" err &&
 
 		envvar=true &&
 		! ( test_bool_env envvar invalid ) 7>err &&
-		grep "error: test_bool_env requires bool values" err
+		test_grep "error: test_bool_env requires bool values" err
 	)
 '
 

@@ -1242,12 +1242,12 @@ test_expect_success 'test_must_fail on a failing git command with env' '
 
 test_expect_success 'test_must_fail rejects a non-git command' '
 	! test_must_fail grep ^$ notafile 2>err &&
-	grep -F "test_must_fail: only '"'"'git'"'"' is allowed" err
+	test_grep -F "test_must_fail: only '"'"'git'"'"' is allowed" err
 '
 
 test_expect_success 'test_must_fail rejects a non-git command with env' '
 	! test_must_fail env var1=a var2=b grep ^$ notafile 2>err &&
-	grep -F "test_must_fail: only '"'"'git'"'"' is allowed" err
+	test_grep -F "test_must_fail: only '"'"'git'"'"' is allowed" err
 '
 
 test_done

@@ -278,9 +278,9 @@ test_expect_success POSIXPERM 'init creates a new deep directory (umask vs. shar
 		git init --bare --shared=0660 newdir/a/b/c &&
 		test_path_is_dir newdir/a/b/c/refs &&
 		ls -ld newdir/a newdir/a/b > lsab.out &&
-		! grep -v "^drwxrw[sx]r-x" lsab.out &&
+		test_grep ! -v "^drwxrw[sx]r-x" lsab.out &&
 		ls -ld newdir/a/b/c > lsc.out &&
-		! grep -v "^drwxrw[sx]---" lsc.out
+		test_grep ! -v "^drwxrw[sx]---" lsc.out
 	)
 '
 

@@ -619,7 +619,7 @@ test_expect_success DEFAULT_REPO_FORMAT 'extensions.refStorage is not allowed wi
 	git init refstorage &&
 	git -C refstorage config extensions.refStorage files &&
 	test_must_fail git -C refstorage rev-parse 2>err &&
-	grep "repo version is 0, but v1-only extension found" err
+	test_grep "repo version is 0, but v1-only extension found" err
 '
 
 test_expect_success DEFAULT_REPO_FORMAT 'extensions.refStorage with files backend' '

@@ -637,7 +637,7 @@ test_expect_success DEFAULT_REPO_FORMAT 'extensions.refStorage with unknown back
 	git -C refstorage config core.repositoryformatversion 1 &&
 	git -C refstorage config extensions.refStorage garbage &&
 	test_must_fail git -C refstorage rev-parse 2>err &&
-	grep "invalid value for ${SQ}extensions.refstorage${SQ}: ${SQ}garbage${SQ}" err
+	test_grep "invalid value for ${SQ}extensions.refstorage${SQ}: ${SQ}garbage${SQ}" err
 '
 
 test_expect_success 'init with GIT_DEFAULT_REF_FORMAT=garbage' '

@@ -848,8 +848,8 @@ test_expect_success MINGW 'redirect std handles' '
 		GIT_REDIRECT_STDOUT=output.txt \
 		GIT_REDIRECT_STDERR="2>&1" \
 		git rev-parse --git-dir --verify refs/invalid &&
-	grep "^\\.git\$" output.txt &&
-	grep "Needed a single revision" output.txt
+	test_grep "^\\.git\$" output.txt &&
+	test_grep "Needed a single revision" output.txt
 '
 
 test_expect_success '--initial-branch' '

@@ -862,14 +862,14 @@ test_expect_success '--initial-branch' '
 	git init --initial-branch=ignore initial-branch-option 2>err &&
 	test_grep "ignored --initial-branch" err &&
 	git -C initial-branch-option symbolic-ref HEAD >actual &&
-	grep hello actual
+	test_grep hello actual
 '
 
 test_expect_success 'overridden default initial branch name (config)' '
 	test_config_global init.defaultBranch nmb &&
 	GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME= git init initial-branch-config &&
 	git -C initial-branch-config symbolic-ref HEAD >actual &&
-	grep nmb actual
+	test_grep nmb actual
 '
 
 test_expect_success 'advice on unconfigured init.defaultBranch' '

@@ -907,7 +907,7 @@ test_expect_success 'overridden default main branch name (env)' '
 	test_config_global init.defaultBranch nmb &&
 	GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=env git init main-branch-env &&
 	git -C main-branch-env symbolic-ref HEAD >actual &&
-	grep env actual
+	test_grep env actual
 '
 
 test_expect_success 'invalid default branch name' '

@@ -790,8 +790,8 @@ test_expect_success 'existing file and directory' '
 	>one &&
 	mkdir top-level-dir &&
 	git check-ignore one top-level-dir >actual &&
-	grep one actual &&
-	grep top-level-dir actual
+	test_grep one actual &&
+	test_grep top-level-dir actual
 '
 
 test_expect_success 'existing directory and file' '

@@ -800,8 +800,8 @@ test_expect_success 'existing directory and file' '
 	>one &&
 	mkdir top-level-dir &&
 	git check-ignore top-level-dir one >actual &&
-	grep one actual &&
-	grep top-level-dir actual
+	test_grep one actual &&
+	test_grep top-level-dir actual
 '
 
 test_expect_success 'exact prefix matching (with root)' '

@@ -35,7 +35,7 @@ test_expect_success PIPE 'setup: .git as a FIFO (named pipe) is rejected' '
 		cd parent/fifo-trap &&
 		mkfifo .git &&
 		test_must_fail git rev-parse --git-dir 2>stderr &&
-		grep "not a regular file" stderr
+		test_grep "not a regular file" stderr
 	)
 '
 

@@ -47,7 +47,7 @@ test_expect_success SYMLINKS,PIPE 'setup: .git as a symlink to a FIFO is rejecte
 		mkfifo target-fifo &&
 		ln -s target-fifo .git &&
 		test_must_fail git rev-parse --git-dir 2>stderr &&
-		grep "not a regular file" stderr
+		test_grep "not a regular file" stderr
 	)
 '
 

@@ -58,7 +58,7 @@ test_expect_success 'setup: .git with garbage content is rejected' '
 		cd parent/garbage-trap &&
 		echo "garbage" >.git &&
 		test_must_fail git rev-parse --git-dir 2>stderr &&
-		grep "invalid gitfile format" stderr
+		test_grep "invalid gitfile format" stderr
 	)
 '
 

@@ -131,8 +131,8 @@ test_expect_success 'git help succeeds without git.html' '
 
 test_expect_success 'git help --user-interfaces' '
 	git help --user-interfaces >help.output &&
-	grep "^   attributes   " help.output &&
-	grep "^   mailmap   " help.output
+	test_grep "^   attributes   " help.output &&
+	test_grep "^   mailmap   " help.output
 '
 
 test_expect_success 'git help -c' '

@@ -16,7 +16,7 @@ fi
 test_expect_success 'test-sha1 detects shattered pdf' '
 	test_must_fail test-tool sha1 <"$TEST_DATA/shattered-1.pdf" 2>err &&
 	test_grep collision err &&
-	grep 38762cf7f55934b34d179ae6a4c80cadccbb7f0a err
+	test_grep 38762cf7f55934b34d179ae6a4c80cadccbb7f0a err
 '
 
 test_done

@@ -88,7 +88,7 @@ test_expect_success 'test-tool env-helper reads config thanks to trace2' '
 	test_must_fail \
 		env HOME="$(pwd)/home" \
 		git config -l 2>err &&
-	grep "exceeded maximum include depth" err &&
+	test_grep "exceeded maximum include depth" err &&
 
 	# This validates that the assumption that we attempt to
 	# read the configuration and fail very early in the start-up

@@ -100,7 +100,7 @@ test_expect_success 'test-tool env-helper reads config thanks to trace2' '
 		test-tool -C no-such-directory \
 		env-helper --type=bool --default=0 \
 		--exit-code GIT_TEST_ENV_HELPER 2>err &&
-	grep "exceeded maximum include depth" err
+	test_grep "exceeded maximum include depth" err
 '
 
 test_done

@@ -731,7 +731,7 @@ test_expect_success 'process filter should restart after unexpected write failur
 		rm -f debug.log &&
 		git checkout --quiet --no-progress . 2>git-stderr.log &&
 
-		grep "smudge write error" git-stderr.log &&
+		test_grep "smudge write error" git-stderr.log &&
 		test_grep "error: external filter" git-stderr.log &&
 
 		cat >expected.log <<-EOF &&

@@ -853,7 +853,7 @@ test_expect_success 'invalid process filter must fail (and not hang!)' '
 
 		cp "$TEST_ROOT/test.o" test.r &&
 		test_must_fail git add . 2>git-stderr.log &&
-		grep "expected git-filter-server" git-stderr.log
+		test_grep "expected git-filter-server" git-stderr.log
 	)
 '
 

@@ -970,7 +970,7 @@ test_expect_success 'missing file in delayed checkout' '
 
 	rm -rf repo-cloned &&
 	test_must_fail git clone repo repo-cloned 2>git-stderr.log &&
-	grep "error: .missing-delay\.a. was not filtered properly" git-stderr.log
+	test_grep "error: .missing-delay\.a. was not filtered properly" git-stderr.log
 '
 
 test_expect_success 'invalid file in delayed checkout' '

@@ -991,7 +991,7 @@ test_expect_success 'invalid file in delayed checkout' '
 
 	rm -rf repo-cloned &&
 	test_must_fail git clone repo repo-cloned 2>git-stderr.log &&
-	grep "error: external filter .* signaled that .unfiltered. is now available although it has not been delayed earlier" git-stderr.log
+	test_grep "error: external filter .* signaled that .unfiltered. is now available although it has not been delayed earlier" git-stderr.log
 '
 
 for mode in 'case' 'utf-8'

@@ -1032,7 +1032,7 @@ do
 
 		git clone $mode-collision $mode-collision-cloned &&
 		# Make sure z was really delayed
-		grep "IN: smudge $dir/z .* \\[DELAYED\\]" $mode-collision-cloned/delayed.log &&
+		test_grep "IN: smudge $dir/z .* \\[DELAYED\\]" $mode-collision-cloned/delayed.log &&
 
 		# Should not create $dir/z at $symlink/z
 		test_path_is_missing $mode-collision/target-dir/z

@@ -1070,7 +1070,7 @@ test_expect_success SYMLINKS,CASE_INSENSITIVE_FS \
 		git commit -m super &&
 
 		git checkout --recurse-submodules . &&
-		grep "IN: smudge A/B/y .* \\[DELAYED\\]" delayed.log &&
+		test_grep "IN: smudge A/B/y .* \\[DELAYED\\]" delayed.log &&
 		test_path_is_missing target-dir/y
 	)
 '

@@ -1161,9 +1161,9 @@ test_expect_success 'delayed checkout correctly reports the number of updated en
 
 		rm *.a &&
 		git checkout . 2>err &&
-		grep "IN: smudge test-delay10.a .* \\[DELAYED\\]" delayed.log &&
-		grep "IN: smudge test-delay11.a .* \\[DELAYED\\]" delayed.log &&
-		grep "Updated 2 paths from the index" err
+		test_grep "IN: smudge test-delay10.a .* \\[DELAYED\\]" delayed.log &&
+		test_grep "IN: smudge test-delay11.a .* \\[DELAYED\\]" delayed.log &&
+		test_grep "Updated 2 paths from the index" err
 	)
 '
 

@@ -20,10 +20,10 @@ test_expect_success 'core.unsetenvvars works' '
 	HOBBES=Calvin &&
 	export HOBBES &&
 	git commit --allow-empty -m with 2>err &&
-	grep Calvin err &&
+	test_grep Calvin err &&
 	git -c core.unsetenvvars=FINDUS,HOBBES,CALVIN \
 		commit --allow-empty -m without 2>err &&
-	! grep Calvin err
+	test_grep ! Calvin err
 '
 
 test_done

@@ -407,12 +407,12 @@ test_expect_success 'strip comments with changed comment string' '
 
 test_expect_success 'newline as commentchar is forbidden' '
 	test_must_fail git -c core.commentChar="$LF" stripspace -s 2>err &&
-	grep "core.commentchar cannot contain newline" err
+	test_grep "core.commentchar cannot contain newline" err
 '
 
 test_expect_success 'empty commentchar is forbidden' '
 	test_must_fail git -c core.commentchar= stripspace -s 2>err &&
-	grep "core.commentchar must have at least one character" err
+	test_grep "core.commentchar must have at least one character" err
 '
 
 test_expect_success '-c with single line' '

@@ -29,7 +29,7 @@ test_expect_success 'PID info not shown by default' '
 		test_must_fail git add . 2>err &&
 		# Should not crash, just show normal error without PID
 		test_grep "Unable to create" err &&
-		! test_grep "is held by process" err
+		test_grep ! "is held by process" err
 	)
 '
 

@@ -324,13 +324,13 @@ test_expect_success 'non ambiguous option (after two options it abbreviates)' '
 
 test_expect_success 'Alias options do not contribute to abbreviation' '
 	test-tool parse-options --alias-source 123 >output &&
-	grep "^string: 123" output &&
+	test_grep "^string: 123" output &&
 	test-tool parse-options --alias-target 123 >output &&
-	grep "^string: 123" output &&
+	test_grep "^string: 123" output &&
 	test_must_fail test-tool parse-options --alias &&
 	GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS=false \
 	test-tool parse-options --alias 123 >output &&
-	grep "^string: 123" output
+	test_grep "^string: 123" output
 '
 
 cat >typo.err <<\EOF

@@ -582,16 +582,16 @@ test_expect_success 'KEEP_UNKNOWN_OPT works' '
 
 test_expect_success 'NO_INTERNAL_HELP works for -h' '
 	test_expect_code 129 test-tool parse-options-flags --no-internal-help cmd -h 2>err &&
-	grep "^error: unknown switch \`h$SQ" err &&
-	grep "^usage: " err
+	test_grep "^error: unknown switch \`h$SQ" err &&
+	test_grep "^usage: " err
 '
 
 for help_opt in help help-all
 do
 	test_expect_success "NO_INTERNAL_HELP works for --$help_opt" "
 		test_expect_code 129 test-tool parse-options-flags --no-internal-help cmd --$help_opt 2>err &&
-		grep '^error: unknown option \`'$help_opt\' err &&
-		grep '^usage: ' err
+		test_grep '^error: unknown option \`'$help_opt\' err &&
+		test_grep '^usage: ' err
 	"
 done
 

@@ -608,38 +608,38 @@ test_expect_success 'KEEP_UNKNOWN_OPT | NO_INTERNAL_HELP works' '
 
 test_expect_success 'subcommand - no subcommand shows error and usage' '
 	test_expect_code 129 test-tool parse-subcommand cmd 2>err &&
-	grep "^error: need a subcommand" err &&
-	grep ^usage: err
+	test_grep "^error: need a subcommand" err &&
+	test_grep ^usage: err
 '
 
 test_expect_success 'subcommand - subcommand after -- shows error and usage' '
 	test_expect_code 129 test-tool parse-subcommand cmd -- subcmd-one 2>err &&
-	grep "^error: need a subcommand" err &&
-	grep ^usage: err
+	test_grep "^error: need a subcommand" err &&
+	test_grep ^usage: err
 '
 
 test_expect_success 'subcommand - subcommand after --end-of-options shows error and usage' '
 	test_expect_code 129 test-tool parse-subcommand cmd --end-of-options subcmd-one 2>err &&
-	grep "^error: need a subcommand" err &&
-	grep ^usage: err
+	test_grep "^error: need a subcommand" err &&
+	test_grep ^usage: err
 '
 
 test_expect_success 'subcommand - unknown subcommand shows error and usage' '
 	test_expect_code 129 test-tool parse-subcommand cmd nope 2>err &&
-	grep "^error: unknown subcommand: \`nope$SQ" err &&
-	grep ^usage: err
+	test_grep "^error: unknown subcommand: \`nope$SQ" err &&
+	test_grep ^usage: err
 '
 
 test_expect_success 'subcommand - subcommands cannot be abbreviated' '
 	test_expect_code 129 test-tool parse-subcommand cmd subcmd-o 2>err &&
-	grep "^error: unknown subcommand: \`subcmd-o$SQ$" err &&
-	grep ^usage: err
+	test_grep "^error: unknown subcommand: \`subcmd-o$SQ$" err &&
+	test_grep ^usage: err
 '
 
 test_expect_success 'subcommand - no negated subcommands' '
 	test_expect_code 129 test-tool parse-subcommand cmd no-subcmd-one 2>err &&
-	grep "^error: unknown subcommand: \`no-subcmd-one$SQ" err &&
-	grep ^usage: err
+	test_grep "^error: unknown subcommand: \`no-subcmd-one$SQ" err &&
+	test_grep ^usage: err
 '
 
 test_expect_success 'subcommand - simple' '

@@ -709,8 +709,8 @@ test_expect_success 'subcommand - SUBCOMMAND_OPTIONAL + subcommand not given + u
 
 test_expect_success 'subcommand - SUBCOMMAND_OPTIONAL + subcommand not given + unknown option' '
 	test_expect_code 129 test-tool parse-subcommand --subcommand-optional cmd --subcommand-opt 2>err &&
-	grep "^error: unknown option" err &&
-	grep ^usage: err
+	test_grep "^error: unknown option" err &&
+	test_grep ^usage: err
 '
 
 test_expect_success 'subcommand - SUBCOMMAND_OPTIONAL | KEEP_UNKNOWN_OPT + subcommand not given + unknown option' '

@@ -778,28 +778,28 @@ test_expect_success 'subcommand - completion helper' '
 
 test_expect_success 'subcommands are incompatible with STOP_AT_NON_OPTION' '
 	test_must_fail test-tool parse-subcommand --stop-at-non-option cmd subcmd-one 2>err &&
-	grep ^BUG err
+	test_grep ^BUG err
 '
 
 test_expect_success 'subcommands are incompatible with KEEP_UNKNOWN_OPT unless in combination with SUBCOMMAND_OPTIONAL' '
 	test_must_fail test-tool parse-subcommand --keep-unknown-opt cmd subcmd-two 2>err &&
-	grep ^BUG err
+	test_grep ^BUG err
 '
 
 test_expect_success 'subcommands are incompatible with KEEP_DASHDASH unless in combination with SUBCOMMAND_OPTIONAL' '
 	test_must_fail test-tool parse-subcommand --keep-dashdash cmd subcmd-two 2>err &&
-	grep ^BUG err
+	test_grep ^BUG err
 '
 
 test_expect_success 'negative unsigned' '
 	test_must_fail test-tool parse-options --unsigned -1 >out 2>err &&
-	grep "non-negative integer" err &&
+	test_grep "non-negative integer" err &&
 	test_must_be_empty out
 '
 
 test_expect_success 'unsigned with units but no numbers' '
 	test_must_fail test-tool parse-options --unsigned m >out 2>err &&
-	grep "non-negative integer" err &&
+	test_grep "non-negative integer" err &&
 	test_must_be_empty out
 '
 

@@ -13,7 +13,7 @@ test_expect_success 'setup ' '
 
 test_expect_success 'tag --contains <existent_tag>' '
 	git tag --contains "v1.0" >actual 2>actual.err &&
-	grep "v1.0" actual &&
+	test_grep "v1.0" actual &&
 	test_line_count = 0 actual.err
 '
 

@@ -33,19 +33,19 @@ test_expect_success 'servers cannot share the same path' '
 test_expect_success 'big response' '
 	test-tool simple-ipc send --token=big >actual &&
 	test_line_count -ge 10000 actual &&
-	grep -q "big: [0]*9999\$" actual
+	test_grep -q "big: [0]*9999\$" actual
 '
 
 test_expect_success 'chunk response' '
 	test-tool simple-ipc send --token=chunk >actual &&
 	test_line_count -ge 10000 actual &&
-	grep -q "big: [0]*9999\$" actual
+	test_grep -q "big: [0]*9999\$" actual
 '
 
 test_expect_success 'slow response' '
 	test-tool simple-ipc send --token=slow >actual &&
 	test_line_count -ge 100 actual &&
-	grep -q "big: [0]*99\$" actual
+	test_grep -q "big: [0]*99\$" actual
 '
 
 # Send an IPC with n=100,000 bytes of ballast.  This should be large enough

@@ -54,7 +54,7 @@ test_expect_success 'slow response' '
 #
 test_expect_success 'sendbytes' '
 	test-tool simple-ipc sendbytes --bytecount=100000 --byte=A >actual &&
-	grep "sent:A00100000 rcvd:A00100000" actual
+	test_grep "sent:A00100000 rcvd:A00100000" actual
 '
 
 # Start a series of <threads> client threads that each make <batchsize>

@@ -93,7 +93,7 @@ test_expect_success 'stress test threads' '
 		--batchsize=13 \
 		>actual &&
 	test_line_count = 92 actual &&
-	grep "good 91" actual &&
+	test_grep "good 91" actual &&
 	grep "sent:A" <actual >actual_a &&
 	cat >expect_a <<-EOF &&
 		sent:A00000019 rcvd:A00000019

@@ -97,7 +97,7 @@ test_expect_success POSIXPERM 'run_command reports EACCES' '
 	chmod -x hello.sh &&
 	test_must_fail test-tool run-command run-command ./hello.sh 2>err &&
 
-	grep "fatal: cannot exec.*hello.sh" err
+	test_grep "fatal: cannot exec.*hello.sh" err
 '
 
 test_expect_success POSIXPERM,SANITY 'unreadable directory in PATH' '

@@ -127,7 +127,7 @@ test_expect_success SYMLINKS 'dir-iterator should not follow symlinks by default
 test_expect_success SYMLINKS 'dir-iterator does not resolve top-level symlinks' '
 	test_must_fail test-tool dir-iterator ./dir5 >out &&
 
-	grep "ENOTDIR" out
+	test_grep "ENOTDIR" out
 '
 
 test_done

@@ -21,23 +21,23 @@ test_expect_success 'run based on configured value' '
 
 	git for-each-repo --config=run.key commit --allow-empty -m "ran" &&
 	git -C one log -1 --pretty=format:%s >message &&
-	grep ran message &&
+	test_grep ran message &&
 	git -C two log -1 --pretty=format:%s >message &&
-	! grep ran message &&
+	test_grep ! ran message &&
 	git -C three log -1 --pretty=format:%s >message &&
-	grep ran message &&
+	test_grep ran message &&
 	git -C ~/four log -1 --pretty=format:%s >message &&
-	grep ran message &&
+	test_grep ran message &&
 
 	git for-each-repo --config=run.key -- commit --allow-empty -m "ran again" &&
 	git -C one log -1 --pretty=format:%s >message &&
-	grep again message &&
+	test_grep again message &&
 	git -C two log -1 --pretty=format:%s >message &&
-	! grep again message &&
+	test_grep ! again message &&
 	git -C three log -1 --pretty=format:%s >message &&
-	grep again message &&
+	test_grep again message &&
 	git -C ~/four log -1 --pretty=format:%s >message &&
-	grep again message &&
+	test_grep again message &&
 
 	git -C three for-each-repo --config=run.key -- \
 		commit --allow-empty -m "ran from worktree" &&

@@ -10,7 +10,7 @@ Verify wrappers and compatibility functions.
 
 test_expect_success 'mktemp to nonexistent directory prints filename' '
 	test_must_fail test-tool mktemp doesnotexist/testXXXXXX 2>err &&
-	grep "doesnotexist/test" err
+	test_grep "doesnotexist/test" err
 '
 
 test_expect_success POSIXPERM,SANITY 'mktemp to unwritable directory prints filename' '

@@ -18,7 +18,7 @@ test_expect_success POSIXPERM,SANITY 'mktemp to unwritable directory prints file
 	test_when_finished "chmod +w cannotwrite" &&
 	chmod -w cannotwrite &&
 	test_must_fail test-tool mktemp cannotwrite/testXXXXXX 2>err &&
-	grep "cannotwrite/test" err
+	test_grep "cannotwrite/test" err
 '
 
 test_expect_success 'git_mkstemps_mode does not fail if fd 0 is not open' '

@@ -33,7 +33,7 @@ test_expect_success 'check for a bug in the regex routines' '
 test_expect_success 'incomplete sideband messages are reassembled' '
 	test-tool pkt-line send-split-sideband >split-sideband &&
 	test-tool pkt-line receive-sideband <split-sideband 2>err &&
-	grep "Hello, world" err
+	test_grep "Hello, world" err
 '
 
 test_expect_success 'eof on sideband message is reported' '

@@ -52,17 +52,17 @@ test_expect_success 'add more packfiles' '
 
 	# HEAD^{tree} is in 2 packfiles
 	test-tool find-pack HEAD^{tree} >head_tree_packs &&
-	grep "$head_commit_pack" head_tree_packs &&
-	grep mypackname1 head_tree_packs &&
-	! grep mypackname2 head_tree_packs &&
+	test_grep "$head_commit_pack" head_tree_packs &&
+	test_grep mypackname1 head_tree_packs &&
+	test_grep ! mypackname2 head_tree_packs &&
 	test-tool find-pack --check-count 2 HEAD^{tree} &&
 	! test-tool find-pack --check-count 1 HEAD^{tree} &&
 
 	# HEAD:five.t is also in 2 packfiles
 	test-tool find-pack HEAD:five.t >five_packs &&
-	grep "$head_commit_pack" five_packs &&
-	! grep mypackname1 five_packs &&
-	grep mypackname2 five_packs &&
+	test_grep "$head_commit_pack" five_packs &&
+	test_grep ! mypackname1 five_packs &&
+	test_grep mypackname2 five_packs &&
 	test-tool find-pack -c 2 HEAD:five.t &&
 	! test-tool find-pack --check-count=0 HEAD:five.t
 '

@@ -40,15 +40,15 @@ test_expect_success 'sanity check "System Info" section' '
 
 	# The beginning should match "git version --build-options" verbatim,
 	# but rather than checking bit-for-bit equality, just test some basics.
-	grep "git version " system &&
-	grep "shell-path: ." system &&
+	test_grep "git version " system &&
+	test_grep "shell-path: ." system &&
 
 	# After the version, there should be some more info.
 	# This is bound to differ from environment to environment,
 	# so we just do some rather high-level checks.
-	grep "uname: ." system &&
-	grep "compiler info: ." system &&
-	grep "zlib." system
+	test_grep "uname: ." system &&
+	test_grep "compiler info: ." system &&
+	test_grep "zlib." system
 '
 
 test_expect_success 'dies if file with same name as report already exists' '

@@ -112,7 +112,7 @@ test_expect_success UNZIP '--diagnose creates diagnostics zip archive' '
 	git bugreport --diagnose -o report -s test >out &&
 
 	zip_path=report/git-diagnostics-test.zip &&
-	grep "Available space" out &&
+	test_grep "Available space" out &&
 	test_path_is_file "$zip_path" &&
 
 	# Check zipped archive content

@@ -120,10 +120,10 @@ test_expect_success UNZIP '--diagnose creates diagnostics zip archive' '
 	test_file_not_empty out &&
 
 	"$GIT_UNZIP" -p "$zip_path" packs-local.txt >out &&
-	grep ".git/objects" out &&
+	test_grep ".git/objects" out &&
 
 	"$GIT_UNZIP" -p "$zip_path" objects-local.txt >out &&
-	grep "^Total: [0-9][0-9]*" out &&
+	test_grep "^Total: [0-9][0-9]*" out &&
 
 	# Should not include .git directory contents by default
 	! "$GIT_UNZIP" -l "$zip_path" | grep ".git/"

@@ -136,7 +136,7 @@ test_expect_success UNZIP '--diagnose=stats excludes .git dir contents' '
 
 	# Includes pack quantity/size info
 	"$GIT_UNZIP" -p "$zip_path" packs-local.txt >out &&
-	grep ".git/objects" out &&
+	test_grep ".git/objects" out &&
 
 	# Does not include .git directory contents
 	! "$GIT_UNZIP" -l "$zip_path" | grep ".git/"

@@ -8,7 +8,7 @@ test_expect_success UNZIP 'creates diagnostics zip archive' '
 	test_when_finished rm -rf report &&
 
 	git diagnose -o report -s test >out &&
-	grep "Available space" out &&
+	test_grep "Available space" out &&
 
 	zip_path=report/git-diagnostics-test.zip &&
 	test_path_is_file "$zip_path" &&

@@ -18,10 +18,10 @@ test_expect_success UNZIP 'creates diagnostics zip archive' '
 	test_file_not_empty out &&
 
 	"$GIT_UNZIP" -p "$zip_path" packs-local.txt >out &&
-	grep ".git/objects" out &&
+	test_grep ".git/objects" out &&
 
 	"$GIT_UNZIP" -p "$zip_path" objects-local.txt >out &&
-	grep "^Total: [0-9][0-9]*" out &&
+	test_grep "^Total: [0-9][0-9]*" out &&
 
 	# Should not include .git directory contents by default
 	! "$GIT_UNZIP" -l "$zip_path" | grep ".git/"

@@ -34,7 +34,7 @@ test_expect_success UNZIP 'counts loose objects' '
 	git diagnose -o test-count -s 1 >out &&
 	zip_path=test-count/git-diagnostics-1.zip &&
 	"$GIT_UNZIP" -p "$zip_path" objects-local.txt >out &&
-	grep "^Total: [1-9][0-9]* loose objects" out
+	test_grep "^Total: [1-9][0-9]* loose objects" out
 '
 
 test_expect_success UNZIP '--mode=stats excludes .git dir contents' '

@@ -45,7 +45,7 @@ test_expect_success UNZIP '--mode=stats excludes .git dir contents' '
 	# Includes pack quantity/size info
 	zip_path=report/git-diagnostics-test.zip &&
 	"$GIT_UNZIP" -p "$zip_path" packs-local.txt >out &&
-	grep ".git/objects" out &&
+	test_grep ".git/objects" out &&
 
 	# Does not include .git directory contents
 	! "$GIT_UNZIP" -l "$zip_path" | grep ".git/"

@@ -59,7 +59,7 @@ test_expect_success UNZIP '--mode=all includes .git dir contents' '
 	# Includes pack quantity/size info
 	zip_path=report/git-diagnostics-test.zip &&
 	"$GIT_UNZIP" -p "$zip_path" packs-local.txt >out &&
-	grep ".git/objects" out &&
+	test_grep ".git/objects" out &&
 
 	# Includes .git directory contents
 	"$GIT_UNZIP" -l "$zip_path" | grep ".git/" &&

@@ -50,7 +50,7 @@ test_expect_success 'merge @{-1}~1' '
 	git checkout main &&
 	git merge @{-1}~1 &&
 	git cat-file commit HEAD >actual &&
-	grep "Merge branch '\''other'\''" actual
+	test_grep "Merge branch '\''other'\''" actual
 '
 
 test_expect_success 'merge @{-100} before checking out that many branches yet' '

@@ -16,7 +16,7 @@ test_expect_success 'sanity: $TEXTDOMAIN is git' '
 '
 
 test_expect_success 'xgettext sanity: Perl _() strings are not extracted' '
-    ! grep "A Perl string xgettext will not get" "$GIT_PO_PATH"/is.po
+    test_grep ! "A Perl string xgettext will not get" "$GIT_PO_PATH"/is.po
 '
 
 test_expect_success 'xgettext sanity: Comment extraction with --add-comments' '

@@ -26,8 +26,8 @@ test_expect_success 'xgettext sanity: Comment extraction with --add-comments' '
 '
 
 test_expect_success 'xgettext sanity: Comment extraction with --add-comments stops at statements' '
-    ! grep "This is a phony" "$GIT_PO_PATH"/is.po &&
-    ! grep "the above comment" "$GIT_PO_PATH"/is.po
+    test_grep ! "This is a phony" "$GIT_PO_PATH"/is.po &&
+    test_grep ! "the above comment" "$GIT_PO_PATH"/is.po
 '
 
 test_expect_success GETTEXT 'sanity: $TEXTDOMAINDIR exists without NO_GETTEXT=YesPlease' '

@@ -44,10 +44,10 @@ test_expect_success GETTEXT 'sanity: Icelandic locale was compiled' '
 test_expect_success GETTEXT_LOCALE 'sanity: gettext("") metadata is OK' '
     # Return value may be non-zero
     LANGUAGE=is LC_ALL="$is_IS_locale" gettext "" >zero-expect &&
-    grep "Project-Id-Version: Git" zero-expect &&
-    grep "Git Mailing List <git@vger.kernel.org>" zero-expect &&
-    grep "Content-Type: text/plain; charset=UTF-8" zero-expect &&
-    grep "Content-Transfer-Encoding: 8bit" zero-expect
+    test_grep "Project-Id-Version: Git" zero-expect &&
+    test_grep "Git Mailing List <git@vger.kernel.org>" zero-expect &&
+    test_grep "Content-Type: text/plain; charset=UTF-8" zero-expect &&
+    test_grep "Content-Transfer-Encoding: 8bit" zero-expect
 '
 
 test_expect_success GETTEXT_LOCALE 'sanity: gettext(unknown) is passed through' '

@@ -12,7 +12,7 @@ test_expect_success 'git show a ISO-8859-1 commit under C locale' '
 	test_commit "iso-c-commit" iso-under-c &&
 	git show >out 2>err &&
 	test_must_be_empty err &&
-	grep -q "iso-c-commit" out
+	test_grep -q "iso-c-commit" out
 '
 
 test_expect_success GETTEXT_LOCALE 'git show a ISO-8859-1 commit under a UTF-8 locale' '

@@ -20,7 +20,7 @@ test_expect_success GETTEXT_LOCALE 'git show a ISO-8859-1 commit under a UTF-8 l
 	test_commit "iso-utf8-commit" iso-under-utf8 &&
 	LANGUAGE=is LC_ALL="$is_IS_locale" git show >out 2>err &&
 	test_must_be_empty err &&
-	grep -q "iso-utf8-commit" out
+	test_grep -q "iso-utf8-commit" out
 '
 
 test_done

@@ -66,22 +66,22 @@ test_expect_success GETTEXT_LOCALE 'gettext: Fetching a UTF-8 msgid -> UTF-8' '
 # eyes.
 test_expect_success GETTEXT_ISO_LOCALE 'gettext: Fetching a UTF-8 msgid -> ISO-8859-1' '
     LANGUAGE=is LC_ALL="$is_IS_iso_locale" gettext "TEST: ‘single’ and “double” quotes" >actual &&
-    grep "einfaldar" actual &&
-    grep "$(echo tvöfaldar | iconv -f UTF-8 -t ISO8859-1)" actual
+    test_grep "einfaldar" actual &&
+    test_grep "$(echo tvöfaldar | iconv -f UTF-8 -t ISO8859-1)" actual
 '
 
 test_expect_success GETTEXT_LOCALE 'gettext.c: git init UTF-8 -> UTF-8' '
     printf "Bjó til tóma Git lind" >expect &&
     LANGUAGE=is LC_ALL="$is_IS_locale" git init repo >actual &&
     test_when_finished "rm -rf repo" &&
-    grep "^$(cat expect) " actual
+    test_grep "^$(cat expect) " actual
 '
 
 test_expect_success GETTEXT_ISO_LOCALE 'gettext.c: git init UTF-8 -> ISO-8859-1' '
     printf "Bjó til tóma Git lind" >expect &&
     LANGUAGE=is LC_ALL="$is_IS_iso_locale" git init repo >actual &&
     test_when_finished "rm -rf repo" &&
-    grep "^$(iconv -f UTF-8 -t ISO8859-1 <expect) " actual
+    test_grep "^$(iconv -f UTF-8 -t ISO8859-1 <expect) " actual
 '
 
 test_done

@@ -333,12 +333,12 @@ test_expect_success 'unsafe URLs are redacted by default' '
 
 	GIT_TRACE2="$(pwd)/trace.normal" \
 		git clone https://user:pwd@example.com/ clone &&
-	! grep user:pwd trace.normal &&
+	test_grep ! user:pwd trace.normal &&
 
 	GIT_TRACE2_REDACT=0 GIT_TRACE2="$(pwd)/unredacted.normal" \
 		git clone https://user:pwd@example.com/ clone2 &&
-	grep "start .* clone https://user:pwd@example.com" unredacted.normal &&
-	grep "remote.origin.url=https://user:pwd@example.com" unredacted.normal
+	test_grep "start .* clone https://user:pwd@example.com" unredacted.normal &&
+	test_grep "remote.origin.url=https://user:pwd@example.com" unredacted.normal
 '
 
 test_done

@@ -283,13 +283,13 @@ test_expect_success 'unsafe URLs are redacted by default' '
 
 	GIT_TRACE2_PERF="$(pwd)/trace.perf" \
 		git clone https://user:pwd@example.com/ clone &&
-	! grep user:pwd trace.perf &&
+	test_grep ! user:pwd trace.perf &&
 
 	GIT_TRACE2_REDACT=0 GIT_TRACE2_PERF="$(pwd)/unredacted.perf" \
 		git clone https://user:pwd@example.com/ clone2 &&
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <unredacted.perf >actual &&
-	grep "d0|main|start|.* clone https://user:pwd@example.com" actual &&
-	grep "d0|main|def_param|.*|remote.origin.url:https://user:pwd@example.com" actual
+	test_grep "d0|main|start|.* clone https://user:pwd@example.com" actual &&
+	test_grep "d0|main|def_param|.*|remote.origin.url:https://user:pwd@example.com" actual
 '
 
 # Confirm that the requested command produces a "cmd_name" and a

@@ -358,13 +358,13 @@ test_expect_success LIBCURL \
 
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <prop.perf >actual &&
 
-	grep "d0|main|cmd_name|.*|_run_dashed_" actual &&
-	grep "d0|main|def_param|.*|cfg.prop.foo:red" actual &&
-	grep "d0|main|def_param|.*|ENV_PROP_FOO:blue" actual &&
+	test_grep "d0|main|cmd_name|.*|_run_dashed_" actual &&
+	test_grep "d0|main|def_param|.*|cfg.prop.foo:red" actual &&
+	test_grep "d0|main|def_param|.*|ENV_PROP_FOO:blue" actual &&
 
-	grep "d1|main|cmd_name|.*|remote-curl" actual &&
-	grep "d1|main|def_param|.*|cfg.prop.foo:red" actual &&
-	grep "d1|main|def_param|.*|ENV_PROP_FOO:blue" actual
+	test_grep "d1|main|cmd_name|.*|remote-curl" actual &&
+	test_grep "d1|main|def_param|.*|cfg.prop.foo:red" actual &&
+	test_grep "d1|main|def_param|.*|ENV_PROP_FOO:blue" actual
 '
 
 # Similarly, `git-http-fetch` is not built from git.c so do a

@@ -389,13 +389,13 @@ test_expect_success LIBCURL \
 
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <prop.perf >actual &&
 
-	grep "d0|main|cmd_name|.*|_run_dashed_" actual &&
-	grep "d0|main|def_param|.*|cfg.prop.foo:red" actual &&
-	grep "d0|main|def_param|.*|ENV_PROP_FOO:blue" actual &&
+	test_grep "d0|main|cmd_name|.*|_run_dashed_" actual &&
+	test_grep "d0|main|def_param|.*|cfg.prop.foo:red" actual &&
+	test_grep "d0|main|def_param|.*|ENV_PROP_FOO:blue" actual &&
 
-	grep "d1|main|cmd_name|.*|http-fetch" actual &&
-	grep "d1|main|def_param|.*|cfg.prop.foo:red" actual &&
-	grep "d1|main|def_param|.*|ENV_PROP_FOO:blue" actual
+	test_grep "d1|main|cmd_name|.*|http-fetch" actual &&
+	test_grep "d1|main|def_param|.*|cfg.prop.foo:red" actual &&
+	test_grep "d1|main|def_param|.*|ENV_PROP_FOO:blue" actual
 '
 
 # Historically, alias expansion explicitly emitted the def_param

@@ -421,22 +421,22 @@ test_expect_success 'expect def_params during git alias expansion' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <prop.perf >actual &&
 
 	# "git xxx" is first mapped to "git-xxx" and the child will fail.
-	grep "d0|main|cmd_name|.*|_run_dashed_ (_run_dashed_)" actual &&
+	test_grep "d0|main|cmd_name|.*|_run_dashed_ (_run_dashed_)" actual &&
 
 	# We unpeel that and substitute "version" into "xxx" (giving
 	# "git version") and update the cmd_name event.
-	grep "d0|main|cmd_name|.*|_run_git_alias_ (_run_dashed_/_run_git_alias_)" actual &&
+	test_grep "d0|main|cmd_name|.*|_run_git_alias_ (_run_dashed_/_run_git_alias_)" actual &&
 
 	# These def_param events could be associated with either of the
 	# above cmd_name events.  It does not matter.
-	grep "d0|main|def_param|.*|cfg.prop.foo:red" actual &&
-	grep "d0|main|def_param|.*|ENV_PROP_FOO:blue" actual &&
+	test_grep "d0|main|def_param|.*|cfg.prop.foo:red" actual &&
+	test_grep "d0|main|def_param|.*|ENV_PROP_FOO:blue" actual &&
 
 	# The "git version" child sees a different cmd_name hierarchy.
 	# Also test the def_param (only for completeness).
-	grep "d1|main|cmd_name|.*|version (_run_dashed_/_run_git_alias_/version)" actual &&
-	grep "d1|main|def_param|.*|cfg.prop.foo:red" actual &&
-	grep "d1|main|def_param|.*|ENV_PROP_FOO:blue" actual
+	test_grep "d1|main|cmd_name|.*|version (_run_dashed_/_run_git_alias_/version)" actual &&
+	test_grep "d1|main|def_param|.*|cfg.prop.foo:red" actual &&
+	test_grep "d1|main|def_param|.*|ENV_PROP_FOO:blue" actual
 '
 
 test_expect_success 'expect def_params during shell alias expansion' '

@@ -456,25 +456,25 @@ test_expect_success 'expect def_params during shell alias expansion' '
 	perl "$TEST_DIRECTORY/t0211/scrub_perf.perl" <prop.perf >actual &&
 
 	# "git xxx" is first mapped to "git-xxx" and the child will fail.
-	grep "d0|main|cmd_name|.*|_run_dashed_ (_run_dashed_)" actual &&
+	test_grep "d0|main|cmd_name|.*|_run_dashed_ (_run_dashed_)" actual &&
 
 	# We unpeel that and substitute "git version" for "git xxx" (as a
 	# shell command.  Another cmd_name event is emitted as we unpeel.
-	grep "d0|main|cmd_name|.*|_run_shell_alias_ (_run_dashed_/_run_shell_alias_)" actual &&
+	test_grep "d0|main|cmd_name|.*|_run_shell_alias_ (_run_dashed_/_run_shell_alias_)" actual &&
 
 	# These def_param events could be associated with either of the
 	# above cmd_name events.  It does not matter.
-	grep "d0|main|def_param|.*|cfg.prop.foo:red" actual &&
-	grep "d0|main|def_param|.*|ENV_PROP_FOO:blue" actual &&
+	test_grep "d0|main|def_param|.*|cfg.prop.foo:red" actual &&
+	test_grep "d0|main|def_param|.*|ENV_PROP_FOO:blue" actual &&
 
 	# We get the following only because we used a git command for the
 	# shell command. In general, it could have been a shell script and
 	# we would see nothing.
 	#
 	# The child knows the cmd_name hierarchy so it includes it.
-	grep "d1|main|cmd_name|.*|version (_run_dashed_/_run_shell_alias_/version)" actual &&
-	grep "d1|main|def_param|.*|cfg.prop.foo:red" actual &&
-	grep "d1|main|def_param|.*|ENV_PROP_FOO:blue" actual
+	test_grep "d1|main|cmd_name|.*|version (_run_dashed_/_run_shell_alias_/version)" actual &&
+	test_grep "d1|main|def_param|.*|cfg.prop.foo:red" actual &&
+	test_grep "d1|main|def_param|.*|ENV_PROP_FOO:blue" actual
 '
 
 test_expect_success 'expect def_params during nested git alias expansion' '

@@ -496,33 +496,33 @@ test_expect_success 'expect def_params during nested git alias expansion' '
 
 	# "git xxx" is first mapped to "git-xxx" and try to spawn "git-xxx"
 	# and the child will fail.
-	grep "d0|main|cmd_name|.*|_run_dashed_ (_run_dashed_)" actual &&
-	grep "d0|main|child_start|.*|.* class:dashed argv:\[git-xxx\]" actual &&
+	test_grep "d0|main|cmd_name|.*|_run_dashed_ (_run_dashed_)" actual &&
+	test_grep "d0|main|child_start|.*|.* class:dashed argv:\[git-xxx\]" actual &&
 
 	# We unpeel that and substitute "yyy" into "xxx" (giving "git yyy")
 	# and spawn "git-yyy" and the child will fail.
-	grep "d0|main|alias|.*|alias:xxx argv:\[yyy\]" actual &&
-	grep "d0|main|cmd_name|.*|_run_dashed_ (_run_dashed_/_run_dashed_)" actual &&
-	grep "d0|main|child_start|.*|.* class:dashed argv:\[git-yyy\]" actual &&
+	test_grep "d0|main|alias|.*|alias:xxx argv:\[yyy\]" actual &&
+	test_grep "d0|main|cmd_name|.*|_run_dashed_ (_run_dashed_/_run_dashed_)" actual &&
+	test_grep "d0|main|child_start|.*|.* class:dashed argv:\[git-yyy\]" actual &&
 
 	# We unpeel that and substitute "version" into "xxx" (giving
 	# "git version") and update the cmd_name event.
-	grep "d0|main|alias|.*|alias:yyy argv:\[version\]" actual &&
-	grep "d0|main|cmd_name|.*|_run_git_alias_ (_run_dashed_/_run_dashed_/_run_git_alias_)" actual &&
+	test_grep "d0|main|alias|.*|alias:yyy argv:\[version\]" actual &&
+	test_grep "d0|main|cmd_name|.*|_run_git_alias_ (_run_dashed_/_run_dashed_/_run_git_alias_)" actual &&
 
 	# These def_param events could be associated with any of the
 	# above cmd_name events.  It does not matter.
 	grep "d0|main|def_param|.*|cfg.prop.foo:red" actual >actual.matches &&
-	grep "d0|main|def_param|.*|ENV_PROP_FOO:blue" actual &&
+	test_grep "d0|main|def_param|.*|ENV_PROP_FOO:blue" actual &&
 
 	# However, we do not want them repeated each time we unpeel.
 	test_line_count = 1 actual.matches &&
 
 	# The "git version" child sees a different cmd_name hierarchy.
 	# Also test the def_param (only for completeness).
-	grep "d1|main|cmd_name|.*|version (_run_dashed_/_run_dashed_/_run_git_alias_/version)" actual &&
-	grep "d1|main|def_param|.*|cfg.prop.foo:red" actual &&
-	grep "d1|main|def_param|.*|ENV_PROP_FOO:blue" actual
+	test_grep "d1|main|cmd_name|.*|version (_run_dashed_/_run_dashed_/_run_git_alias_/version)" actual &&
+	test_grep "d1|main|def_param|.*|cfg.prop.foo:red" actual &&
+	test_grep "d1|main|def_param|.*|ENV_PROP_FOO:blue" actual
 '
 
 test_done

@@ -332,7 +332,7 @@ test_expect_success 'unsafe URLs are redacted by default in cmd_start events' '
 
 	GIT_TRACE2_EVENT="$(pwd)/trace.event" \
 		test-tool trace2 300redact_start git clone https://user:pwd@example.com/ clone2 &&
-	! grep user:pwd trace.event
+	test_grep ! user:pwd trace.event
 '
 
 test_expect_success 'unsafe URLs are redacted by default in child_start events' '

@@ -341,7 +341,7 @@ test_expect_success 'unsafe URLs are redacted by default in child_start events'
 
 	GIT_TRACE2_EVENT="$(pwd)/trace.event" \
 		test-tool trace2 301redact_child_start git clone https://user:pwd@example.com/ clone2 &&
-	! grep user:pwd trace.event
+	test_grep ! user:pwd trace.event
 '
 
 test_expect_success 'unsafe URLs are redacted by default in exec events' '

@@ -350,7 +350,7 @@ test_expect_success 'unsafe URLs are redacted by default in exec events' '
 
 	GIT_TRACE2_EVENT="$(pwd)/trace.event" \
 		test-tool trace2 302redact_exec git clone https://user:pwd@example.com/ clone2 &&
-	! grep user:pwd trace.event
+	test_grep ! user:pwd trace.event
 '
 
 test_expect_success 'unsafe URLs are redacted by default in def_param events' '

@@ -359,7 +359,7 @@ test_expect_success 'unsafe URLs are redacted by default in def_param events' '
 
 	GIT_TRACE2_EVENT="$(pwd)/trace.event" \
 		test-tool trace2 303redact_def_param url https://user:pwd@example.com/ &&
-	! grep user:pwd trace.event
+	test_grep ! user:pwd trace.event
 '
 
 test_done

@@ -1014,7 +1014,7 @@ test_expect_success 'credential config with partial URLs' '
 	do
 		git -c credential.$partial.helper=yep \
 			credential fill <stdin >stdout &&
-		grep yep stdout ||
+		test_grep yep stdout ||
 		return 1
 	done &&
 

@@ -1030,7 +1030,7 @@ test_expect_success 'credential config with partial URLs' '
 	do
 		git -c credential.$partial.helper=yep \
 			credential fill <stdin >stdout &&
-		! grep yep stdout ||
+		test_grep ! yep stdout ||
 		return 1
 	done &&
 

@@ -206,7 +206,7 @@ test_expect_success 'fetching of missing objects' '
 	git -C repo cat-file -p "$HASH" 2>err &&
 
 	# Ensure that no spurious FETCH_HEAD messages are written
-	! grep FETCH_HEAD err &&
+	test_grep ! FETCH_HEAD err &&
 
 	# Ensure that the .promisor file is written, and check that its
 	# associated packfile contains the object

@@ -214,7 +214,7 @@ test_expect_success 'fetching of missing objects' '
 	test_line_count = 1 promisorlist &&
 	IDX=$(sed "s/promisor$/idx/" promisorlist) &&
 	git verify-pack --verbose "$IDX" >out &&
-	grep "$HASH" out
+	test_grep "$HASH" out
 '
 
 test_expect_success 'fetching of a promised object that promisor remote no longer has' '

@@ -228,7 +228,7 @@ test_expect_success 'fetching of a promised object that promisor remote no longe
 
 	rm -rf unreliable-server/.git/objects/* &&
 	test_must_fail git -C unreliable-client checkout HEAD 2>err &&
-	grep "could not fetch.*from promisor remote" err
+	test_grep "could not fetch.*from promisor remote" err
 '
 
 test_expect_success 'fetching of missing objects works with ref-in-want enabled' '

@@ -240,7 +240,7 @@ test_expect_success 'fetching of missing objects works with ref-in-want enabled'
 	rm -rf repo/.git/objects/* &&
 	rm -f trace &&
 	GIT_TRACE_PACKET="$(pwd)/trace" git -C repo cat-file -p "$HASH" &&
-	grep "fetch< fetch=.*ref-in-want" trace
+	test_grep "fetch< fetch=.*ref-in-want" trace
 '
 
 test_expect_success 'fetching from another promisor remote' '

@@ -263,7 +263,7 @@ test_expect_success 'fetching from another promisor remote' '
 	test_line_count = 1 promisorlist &&
 	IDX=$(sed "s/promisor$/idx/" promisorlist) &&
 	git verify-pack --verbose "$IDX" >out &&
-	grep "$HASH2" out
+	test_grep "$HASH2" out
 '
 
 test_expect_success 'fetching with --filter configures a promisor remote' '

@@ -286,7 +286,7 @@ test_expect_success 'fetching with --filter configures a promisor remote' '
 	test_line_count = 1 promisorlist &&
 	IDX=$(sed "s/promisor$/idx/" promisorlist) &&
 	git verify-pack --verbose "$IDX" >out &&
-	grep "$HASH3" out
+	test_grep "$HASH3" out
 '
 
 test_expect_success 'fetching of missing blobs works' '

@@ -327,8 +327,8 @@ test_expect_success 'fetching of missing trees does not fetch blobs' '
 
 	# Ensure that the tree, but not the blob, is fetched
 	git -C repo rev-list --objects --missing=print $(cat treehash) >objects &&
-	grep "^$(cat treehash)" objects &&
-	grep "^[?]$(cat blobhash)" objects
+	test_grep "^$(cat treehash)" objects &&
+	test_grep "^[?]$(cat blobhash)" objects
 '
 
 test_expect_success 'rev-list stops traversal at missing and promised commit' '

@@ -343,8 +343,8 @@ test_expect_success 'rev-list stops traversal at missing and promised commit' '
 	git -C repo config core.repositoryformatversion 1 &&
 	git -C repo config extensions.partialclone "arbitrary string" &&
 	git -C repo rev-list --exclude-promisor-objects --objects bar >out &&
-	grep $(git -C repo rev-parse bar) out &&
-	! grep $FOO out
+	test_grep $(git -C repo rev-parse bar) out &&
+	test_grep ! $FOO out
 '
 
 test_expect_success 'missing tree objects with --missing=allow-promisor and --exclude-promisor-objects' '

@@ -413,10 +413,10 @@ test_expect_success 'rev-list stops traversal at missing and promised tree' '
 	git -C repo config core.repositoryformatversion 1 &&
 	git -C repo config extensions.partialclone "arbitrary string" &&
 	git -C repo rev-list --exclude-promisor-objects --objects HEAD >out &&
-	grep $(git -C repo rev-parse foo) out &&
-	! grep $TREE out &&
-	grep $(git -C repo rev-parse HEAD) out &&
-	! grep $TREE2 out
+	test_grep $(git -C repo rev-parse foo) out &&
+	test_grep ! $TREE out &&
+	test_grep $(git -C repo rev-parse HEAD) out &&
+	test_grep ! $TREE2 out
 '
 
 test_expect_success 'rev-list stops traversal at missing and promised blob' '

@@ -432,8 +432,8 @@ test_expect_success 'rev-list stops traversal at missing and promised blob' '
 	git -C repo config core.repositoryformatversion 1 &&
 	git -C repo config extensions.partialclone "arbitrary string" &&
 	git -C repo rev-list --exclude-promisor-objects --objects HEAD >out &&
-	grep $(git -C repo rev-parse HEAD) out &&
-	! grep $BLOB out
+	test_grep $(git -C repo rev-parse HEAD) out &&
+	test_grep ! $BLOB out
 '
 
 test_expect_success 'rev-list stops traversal at promisor commit, tree, and blob' '

@@ -451,10 +451,10 @@ test_expect_success 'rev-list stops traversal at promisor commit, tree, and blob
 	git -C repo config core.repositoryformatversion 1 &&
 	git -C repo config extensions.partialclone "arbitrary string" &&
 	git -C repo rev-list --exclude-promisor-objects --objects HEAD >out &&
-	! grep $COMMIT out &&
-	! grep $TREE out &&
-	! grep $BLOB out &&
-	grep $(git -C repo rev-parse bar) out  # sanity check that some walking was done
+	test_grep ! $COMMIT out &&
+	test_grep ! $TREE out &&
+	test_grep ! $BLOB out &&
+	test_grep $(git -C repo rev-parse bar) out  # sanity check that some walking was done
 '
 
 test_expect_success 'rev-list dies for missing objects on cmd line' '

@@ -523,10 +523,10 @@ test_expect_success 'gc repacks promisor objects separately from non-promisor ob
 	test_line_count = 1 promisorlist &&
 	PROMISOR_PACKFILE=$(sed "s/.promisor/.pack/" <promisorlist) &&
 	git verify-pack $PROMISOR_PACKFILE -v >out &&
-	grep "$TREE_ONE" out &&
-	grep "$TREE_TWO" out &&
-	! grep "$(git -C repo rev-parse one)" out &&
-	! grep "$(git -C repo rev-parse two)" out &&
+	test_grep "$TREE_ONE" out &&
+	test_grep "$TREE_TWO" out &&
+	test_grep ! "$(git -C repo rev-parse one)" out &&
+	test_grep ! "$(git -C repo rev-parse two)" out &&
 
 	# Remove the promisor packfile and associated files
 	rm $(sed "s/.promisor//" <promisorlist).* &&

@@ -536,10 +536,10 @@ test_expect_success 'gc repacks promisor objects separately from non-promisor ob
 	ls repo/.git/objects/pack/pack-*.pack >packlist &&
 	test_line_count = 1 packlist &&
 	git verify-pack repo/.git/objects/pack/pack-*.pack -v >out &&
-	grep "$(git -C repo rev-parse one)" out &&
-	grep "$(git -C repo rev-parse two)" out &&
-	! grep "$TREE_ONE" out &&
-	! grep "$TREE_TWO" out
+	test_grep "$(git -C repo rev-parse one)" out &&
+	test_grep "$(git -C repo rev-parse two)" out &&
+	test_grep ! "$TREE_ONE" out &&
+	test_grep ! "$TREE_TWO" out
 '
 
 test_expect_success 'gc does not repack promisor objects if there are none' '

@@ -616,8 +616,8 @@ test_expect_success 'gc stops traversal when a missing but promised object is re
 	ls repo/.git/objects/pack/pack-*.pack >packlist &&
 	test_line_count = 1 packlist &&
 	git verify-pack repo/.git/objects/pack/pack-*.pack -v >out &&
-	grep "$(git -C repo rev-parse HEAD)" out &&
-	! grep "$TREE_HASH" out
+	test_grep "$(git -C repo rev-parse HEAD)" out &&
+	test_grep ! "$TREE_HASH" out
 '
 
 test_expect_success 'do not fetch when checking existence of tree we construct ourselves' '

@@ -647,10 +647,10 @@ test_expect_success 'exact rename does not need to fetch the blob lazily' '
 
 	git clone --filter=blob:none --bare "file://$(pwd)/repo" partial.git &&
 	git -C partial.git rev-list --objects --missing=print HEAD >out &&
-	grep "[?]$FILE_HASH" out &&
+	test_grep "[?]$FILE_HASH" out &&
 	git -C partial.git log --follow -- new-file.txt &&
 	git -C partial.git rev-list --objects --missing=print HEAD >out &&
-	grep "[?]$FILE_HASH" out
+	test_grep "[?]$FILE_HASH" out
 '
 
 test_expect_success 'lazy-fetch when accessing object not in the_repository' '

@@ -665,7 +665,7 @@ test_expect_success 'lazy-fetch when accessing object not in the_repository' '
 
 	# Sanity check that the file is missing
 	git -C partial.git rev-list --objects --missing=print HEAD >out &&
-	grep "[?]$FILE_HASH" out &&
+	test_grep "[?]$FILE_HASH" out &&
 
 	# The no-lazy-fetch mechanism prevents Git from fetching
 	test_must_fail env GIT_NO_LAZY_FETCH=1 \

@@ -680,7 +680,7 @@ test_expect_success 'lazy-fetch when accessing object not in the_repository' '
 
 	# Sanity check that the file is still missing
 	git -C partial.git rev-list --objects --missing=print HEAD >out &&
-	grep "[?]$FILE_HASH" out &&
+	test_grep "[?]$FILE_HASH" out &&
 
 	git -C full cat-file -s "$FILE_HASH" >expect &&
 	test-tool partial-clone object-info partial.git "$FILE_HASH" >actual &&

@@ -688,7 +688,7 @@ test_expect_success 'lazy-fetch when accessing object not in the_repository' '
 
 	# Sanity check that the file is now present
 	git -C partial.git rev-list --objects --missing=print HEAD >out &&
-	! grep "[?]$FILE_HASH" out
+	test_grep ! "[?]$FILE_HASH" out
 '
 
 test_expect_success 'push should not fetch new commit objects' '

@@ -705,9 +705,9 @@ test_expect_success 'push should not fetch new commit objects' '
 	COMMIT=$(git -C server rev-parse server2) &&
 
 	test_must_fail git -C client push 2>err &&
-	grep "fetch first" err &&
+	test_grep "fetch first" err &&
 	git -C client rev-list --objects --missing=print "$COMMIT" >objects &&
-	grep "^[?]$COMMIT" objects
+	test_grep "^[?]$COMMIT" objects
 '
 
 test_expect_success 'setup for promisor.quiet tests' '

@@ -750,7 +750,7 @@ test_expect_success TTY 'promisor.quiet=false shows progress messages' '
 	test_terminal git -C repo cat-file -p foo:foo.t 2>err &&
 
 	# Ensure that progress messages are written
-	grep "Receiving objects" err
+	test_grep "Receiving objects" err
 '
 
 test_expect_success TTY 'promisor.quiet=true does not show progress messages' '

@@ -761,7 +761,7 @@ test_expect_success TTY 'promisor.quiet=true does not show progress messages' '
 	test_terminal git -C repo cat-file -p foo:foo.t 2>err &&
 
 	# Ensure that no progress messages are written
-	! grep "Receiving objects" err
+	test_grep ! "Receiving objects" err
 '
 
 test_expect_success TTY 'promisor.quiet=unconfigured shows progress messages' '

@@ -771,7 +771,7 @@ test_expect_success TTY 'promisor.quiet=unconfigured shows progress messages' '
 	test_terminal git -C repo cat-file -p foo:foo.t 2>err &&
 
 	# Ensure that progress messages are written
-	grep "Receiving objects" err
+	test_grep "Receiving objects" err
 '
 
 test_expect_success 'promisor.quiet from submodule repo is honored' '

@@ -819,7 +819,7 @@ test_expect_success 'fetching of missing objects from an HTTP server' '
 	test_line_count = 1 promisorlist &&
 	IDX=$(sed "s/promisor$/idx/" promisorlist) &&
 	git verify-pack --verbose "$IDX" >out &&
-	grep "$HASH" out
+	test_grep "$HASH" out
 '
 
 # DO NOT add non-httpd-specific tests here, because the last part of this

@@ -87,7 +87,7 @@ do
 	# -h output assertions
 	test_expect_success "$builtin -h output has no \t" '
 		h2s="$(help_to_synopsis "$builtin")" &&
-		! grep "$HT" "$h2s"
+		test_grep ! "$HT" "$h2s"
 	'
 
 	test_expect_success "$builtin -h output has dashed labels" '

@@ -320,8 +320,8 @@ test_expect_success 'progress generates traces' '
 
 	# t0212/parse_events.perl intentionally omits regions and data.
 	test_region progress "Working hard" trace.event &&
-	grep "\"key\":\"total_objects\",\"value\":\"40\"" trace.event &&
-	grep "\"key\":\"total_bytes\",\"value\":\"409600\"" trace.event
+	test_grep "\"key\":\"total_objects\",\"value\":\"40\"" trace.event &&
+	test_grep "\"key\":\"total_bytes\",\"value\":\"409600\"" trace.event
 '
 
 test_expect_success 'progress generates traces: stop / start' '

@@ -344,8 +344,8 @@ test_expect_success 'progress generates traces: start without stop' '
 	LSAN_OPTIONS=detect_leaks=0 \
 	test-tool progress \
 		<in 2>stderr &&
-	grep region_enter.*progress trace-start.event &&
-	! grep region_leave.*progress trace-start.event
+	test_grep region_enter.*progress trace-start.event &&
+	test_grep ! region_leave.*progress trace-start.event
 '
 
 test_expect_success 'progress generates traces: stop without start' '

@@ -355,8 +355,8 @@ test_expect_success 'progress generates traces: stop without start' '
 
 	GIT_TRACE2_EVENT="$PWD/trace-stop.event" test-tool progress \
 		<in 2>stderr &&
-	! grep region_enter.*progress trace-stop.event &&
-	! grep region_leave.*progress trace-stop.event
+	test_grep ! region_enter.*progress trace-stop.event &&
+	test_grep ! region_leave.*progress trace-stop.event
 '
 
 test_expect_success 'progress generates traces: start with active progress bar (no stops)' '

@@ -369,9 +369,9 @@ test_expect_success 'progress generates traces: start with active progress bar (
 	LSAN_OPTIONS=detect_leaks=0 \
 	test-tool progress \
 		<in 2>stderr &&
-	grep region_enter.*progress.*One trace-2start.event &&
-	grep region_enter.*progress.*Two trace-2start.event &&
-	! grep region_leave trace-2start.event
+	test_grep region_enter.*progress.*One trace-2start.event &&
+	test_grep region_enter.*progress.*Two trace-2start.event &&
+	test_grep ! region_leave trace-2start.event
 '
 
 test_done

@@ -776,11 +776,11 @@ test_expect_success 'reflog: can delete separate reflog entries' '
 		test_commit file3 &&
 		test_commit file4 &&
 		git reflog >actual &&
-		grep file3 actual &&
+		test_grep file3 actual &&
 
 		git reflog delete HEAD@{1} &&
 		git reflog >actual &&
-		! grep file3 actual
+		test_grep ! file3 actual
 	)
 '
 

@@ -902,8 +902,8 @@ test_expect_success 'reflog: garbage collection deletes reflog entries' '
 		done &&
 		git reflog refs/heads/main >actual &&
 		test_line_count = 10 actual &&
-		grep "commit (initial): number 1" actual &&
-		grep "commit: number 10" actual &&
+		test_grep "commit (initial): number 1" actual &&
+		test_grep "commit: number 10" actual &&
 
 		git gc &&
 		git reflog refs/heads/main >actual &&

@@ -142,8 +142,8 @@ test_expect_success '3-way not overwriting local changes (our side)' '
 
 	echo >>file1 "local changes" &&
 	read_tree_u_must_succeed -m -u branch-point side-a side-b &&
-	grep "new line to be kept" file1 &&
-	grep "local changes" file1
+	test_grep "new line to be kept" file1 &&
+	test_grep "local changes" file1
 
 '
 

@@ -156,8 +156,8 @@ test_expect_success '3-way not overwriting local changes (their side)' '
 
 	echo >>file2 "local changes" &&
 	read_tree_u_must_fail -m -u branch-point side-a side-b &&
-	! grep "new line to be kept" file2 &&
-	grep "local changes" file2
+	test_grep ! "new line to be kept" file2 &&
+	test_grep "local changes" file2
 
 '
 

@@ -696,8 +696,8 @@ test_expect_success '%(deltabase) reports packed delta bases' '
 	git repack -ad &&
 	git cat-file --batch-check="%(deltabase)" <blobs >actual &&
 	{
-		grep "$(git rev-parse HEAD:foo)" actual ||
-		grep "$(git rev-parse HEAD:foo-plus)" actual
+		test_grep "$(git rev-parse HEAD:foo)" actual ||
+		test_grep "$(git rev-parse HEAD:foo-plus)" actual
 	}
 '
 

@@ -826,7 +826,7 @@ test_expect_success 'cat-file -t and -s on corrupt loose object' '
 		# Swap the two to corrupt the repository
 		mv -f "$other_path" "$empty_path" &&
 		test_must_fail git fsck 2>err.fsck &&
-		grep "hash-path mismatch" err.fsck &&
+		test_grep "hash-path mismatch" err.fsck &&
 
 		# confirm that cat-file is reading the new swapped-in
 		# blob...

@@ -1318,37 +1318,37 @@ test_expect_success 'cat-file --batch-all-objects --batch-check ignores replace'
 test_expect_success 'batch-command empty command' '
 	echo "" >cmd &&
 	test_expect_code 128 git cat-file --batch-command <cmd 2>err &&
-	grep "^fatal:.*empty command in input.*" err
+	test_grep "^fatal:.*empty command in input.*" err
 '
 
 test_expect_success 'batch-command whitespace before command' '
 	echo " info deadbeef" >cmd &&
 	test_expect_code 128 git cat-file --batch-command <cmd 2>err &&
-	grep "^fatal:.*whitespace before command.*" err
+	test_grep "^fatal:.*whitespace before command.*" err
 '
 
 test_expect_success 'batch-command unknown command' '
 	echo unknown_command >cmd &&
 	test_expect_code 128 git cat-file --batch-command <cmd 2>err &&
-	grep "^fatal:.*unknown command.*" err
+	test_grep "^fatal:.*unknown command.*" err
 '
 
 test_expect_success 'batch-command missing arguments' '
 	echo "info" >cmd &&
 	test_expect_code 128 git cat-file --batch-command <cmd 2>err &&
-	grep "^fatal:.*info requires arguments.*" err
+	test_grep "^fatal:.*info requires arguments.*" err
 '
 
 test_expect_success 'batch-command flush with arguments' '
 	echo "flush arg" >cmd &&
 	test_expect_code 128 git cat-file --batch-command --buffer <cmd 2>err &&
-	grep "^fatal:.*flush takes no arguments.*" err
+	test_grep "^fatal:.*flush takes no arguments.*" err
 '
 
 test_expect_success 'batch-command flush without --buffer' '
 	echo "flush" >cmd &&
 	test_expect_code 128 git cat-file --batch-command <cmd 2>err &&
-	grep "^fatal:.*flush is only for --buffer mode.*" err
+	test_grep "^fatal:.*flush is only for --buffer mode.*" err
 '
 
 perl_script='

@@ -202,7 +202,7 @@ done
 test_expect_success 'too-short tree' '
 	echo abc >malformed-tree &&
 	test_must_fail git hash-object -t tree malformed-tree 2>err &&
-	grep "too-short tree object" err
+	test_grep "too-short tree object" err
 '
 
 test_expect_success PERL_TEST_HELPERS 'malformed mode in tree' '

@@ -210,7 +210,7 @@ test_expect_success PERL_TEST_HELPERS 'malformed mode in tree' '
 	bin_oid=$(echo $hex_oid | hex2oct) &&
 	printf "9100644 \0$bin_oid" >tree-with-malformed-mode &&
 	test_must_fail git hash-object -t tree tree-with-malformed-mode 2>err &&
-	grep "malformed mode in tree entry" err
+	test_grep "malformed mode in tree entry" err
 '
 
 test_expect_success PERL_TEST_HELPERS 'empty filename in tree' '

@@ -218,7 +218,7 @@ test_expect_success PERL_TEST_HELPERS 'empty filename in tree' '
 	bin_oid=$(echo $hex_oid | hex2oct) &&
 	printf "100644 \0$bin_oid" >tree-with-empty-filename &&
 	test_must_fail git hash-object -t tree tree-with-empty-filename 2>err &&
-	grep "empty filename in tree entry" err
+	test_grep "empty filename in tree entry" err
 '
 
 test_expect_success PERL_TEST_HELPERS 'duplicate filename in tree' '

@@ -229,7 +229,7 @@ test_expect_success PERL_TEST_HELPERS 'duplicate filename in tree' '
 		printf "100644 file\0$bin_oid"
 	} >tree-with-duplicate-filename &&
 	test_must_fail git hash-object -t tree tree-with-duplicate-filename 2>err &&
-	grep "duplicateEntries" err
+	test_grep "duplicateEntries" err
 '
 
 test_expect_success 'corrupt commit' '

@@ -196,7 +196,7 @@ test_expect_success 'read-tree will not throw away dirty changes, non-sparse' '
 	echo dirty >init.t &&
 	read_tree_u_must_fail -m -u HEAD^ &&
 	test_path_is_file init.t &&
-	grep -q dirty init.t
+	test_grep -q dirty init.t
 '
 
 test_expect_success 'read-tree will not throw away dirty changes, sparse' '

@@ -207,7 +207,7 @@ test_expect_success 'read-tree will not throw away dirty changes, sparse' '
 	echo sub/added >.git/info/sparse-checkout &&
 	read_tree_u_must_fail -m -u HEAD^ &&
 	test_path_is_file init.t &&
-	grep -q dirty init.t
+	test_grep -q dirty init.t
 '
 
 test_expect_success 'read-tree updates worktree, dirty case' '

@@ -215,7 +215,7 @@ test_expect_success 'read-tree updates worktree, dirty case' '
 	git checkout -f top &&
 	echo dirty >init.t &&
 	read_tree_u_must_fail -m -u HEAD^ &&
-	grep -q dirty init.t &&
+	test_grep -q dirty init.t &&
 	rm init.t
 '
 

@@ -224,7 +224,7 @@ test_expect_success 'read-tree removes worktree, dirty case' '
 	git checkout -f top &&
 	echo dirty >added &&
 	read_tree_u_must_succeed -m -u HEAD^ &&
-	grep -q dirty added
+	test_grep -q dirty added
 '
 
 test_expect_success 'read-tree adds to worktree, absent case' '

@@ -240,7 +240,7 @@ test_expect_success 'read-tree adds to worktree, dirty case' '
 	mkdir sub &&
 	echo dirty >sub/added &&
 	read_tree_u_must_succeed -u -m HEAD^ &&
-	grep -q dirty sub/added
+	test_grep -q dirty sub/added
 '
 
 test_expect_success 'index removal and worktree narrowing at the same time' '

@@ -8,7 +8,7 @@ test_description='adding and checking out large blobs'
 test_expect_success 'core.bigFileThreshold must be non-negative' '
 	: >input &&
 	test_must_fail git -c core.bigFileThreshold=-1 hash-object input >out 2>err &&
-	grep "bad numeric config value" err &&
+	test_grep "bad numeric config value" err &&
 	test_must_be_empty out
 '
 

@@ -148,12 +148,12 @@ test_expect_success 'diff --stat' '
 
 test_expect_success 'diff' '
 	git diff HEAD^ HEAD >actual &&
-	grep "Binary files.*differ" actual
+	test_grep "Binary files.*differ" actual
 '
 
 test_expect_success 'diff --cached' '
 	git diff --cached HEAD^ >actual &&
-	grep "Binary files.*differ" actual
+	test_grep "Binary files.*differ" actual
 '
 
 test_expect_success 'hash-object' '

@@ -129,7 +129,7 @@ test_expect_success 'switching to cone mode with non-cone mode patterns' '
 		git sparse-checkout add dir &&
 		git config --worktree core.sparseCheckoutCone true &&
 		test_must_fail git sparse-checkout add dir 2>err &&
-		grep "existing sparse-checkout patterns do not use cone mode" err
+		test_grep "existing sparse-checkout patterns do not use cone mode" err
 	)
 '
 

@@ -803,7 +803,7 @@ test_expect_success 'cone mode clears ignored subdirectories' '
 	# When an untracked file is in the way, all untracked files
 	# (even ignored files) are preserved.
 	git -C repo sparse-checkout set folder1 2>err &&
-	grep "contains untracked files" err &&
+	test_grep "contains untracked files" err &&
 	test_path_is_file repo/deep/deeper2/ignored.o &&
 	test_path_is_file repo/deep/deeper2/untracked &&
 

@@ -882,8 +882,8 @@ test_expect_success 'malformed cone-mode patterns' '
 	# of using the cone-mode translation to a set of directories.
 	git -C repo sparse-checkout list >actual 2>err &&
 	test_cmp repo/.git/info/sparse-checkout actual &&
-	grep "warning: your sparse-checkout file may have issues: pattern .* is repeated" err &&
-	grep "warning: disabling cone pattern matching" err
+	test_grep "warning: your sparse-checkout file may have issues: pattern .* is repeated" err &&
+	test_grep "warning: disabling cone pattern matching" err
 '
 
 test_expect_success 'set from subdir pays attention to prefix' '

@@ -917,34 +917,34 @@ test_expect_success 'set from subdir in non-cone mode throws an error' '
 	git -C repo sparse-checkout disable &&
 	test_must_fail git -C repo/deep sparse-checkout set --no-cone deeper2 ../folder1 2>error &&
 
-	grep "run from the toplevel directory in non-cone mode" error
+	test_grep "run from the toplevel directory in non-cone mode" error
 '
 
 test_expect_success 'set from subdir in non-cone mode throws an error' '
 	git -C repo sparse-checkout set --no-cone deep/deeper2 &&
 	test_must_fail git -C repo/deep sparse-checkout add deeper1/deepest ../folder1 2>error &&
 
-	grep "run from the toplevel directory in non-cone mode" error
+	test_grep "run from the toplevel directory in non-cone mode" error
 '
 
 test_expect_success 'by default, cone mode will error out when passed files' '
 	git -C repo sparse-checkout reapply --cone &&
 	test_must_fail git -C repo sparse-checkout add .gitignore 2>error &&
 
-	grep ".gitignore.*is not a directory" error
+	test_grep ".gitignore.*is not a directory" error
 '
 
 test_expect_success 'error on mistyped command line options' '
 	test_must_fail git -C repo sparse-checkout add --sikp-checks .gitignore 2>error &&
 
-	grep "unknown option.*sikp-checks" error
+	test_grep "unknown option.*sikp-checks" error
 '
 
 test_expect_success 'by default, non-cone mode will warn on individual files' '
 	git -C repo sparse-checkout reapply --no-cone &&
 	git -C repo sparse-checkout add .gitignore 2>warning &&
 
-	grep "pass a leading slash before paths.*if you want a single file" warning
+	test_grep "pass a leading slash before paths.*if you want a single file" warning
 '
 
 test_expect_success 'setup bare repo' '

@@ -1108,11 +1108,11 @@ test_expect_success 'clean' '
 	touch repo/folder1/extra/inside/file &&
 
 	test_must_fail git -C repo sparse-checkout clean 2>err &&
-	grep "refusing to clean" err &&
+	test_grep "refusing to clean" err &&
 
 	git -C repo config clean.requireForce true &&
 	test_must_fail git -C repo sparse-checkout clean 2>err &&
-	grep "refusing to clean" err &&
+	test_grep "refusing to clean" err &&
 
 	cat >expect <<-\EOF &&
 	Would remove deep/deeper2/

@@ -1255,7 +1255,7 @@ test_expect_success 'sparse-checkout operations with merge conflicts' '
 		test_must_fail git merge -m "will-conflict" right &&
 
 		test_must_fail git sparse-checkout clean -f 2>err &&
-		grep "failed to convert index to a sparse index" err &&
+		test_grep "failed to convert index to a sparse index" err &&
 
 		echo merged >folder1/even/more/dirs/file &&
 		git add --sparse folder1 &&

@@ -454,10 +454,10 @@ test_expect_success 'add outside sparse cone' '
 	run_on_sparse ../edit-contents folder1/a &&
 	run_on_sparse ../edit-contents folder1/newfile &&
 	test_sparse_match test_must_fail git add folder1/a &&
-	grep "Disable or modify the sparsity rules" sparse-checkout-err &&
+	test_grep "Disable or modify the sparsity rules" sparse-checkout-err &&
 	test_sparse_unstaged folder1/a &&
 	test_sparse_match test_must_fail git add folder1/newfile &&
-	grep "Disable or modify the sparsity rules" sparse-checkout-err &&
+	test_grep "Disable or modify the sparsity rules" sparse-checkout-err &&
 	test_sparse_unstaged folder1/newfile
 '
 

@@ -509,13 +509,13 @@ test_expect_success 'status/add: outside sparse cone' '
 
 	# Adding the path outside of the sparse-checkout cone should fail.
 	test_sparse_match test_must_fail git add folder1/a &&
-	grep "Disable or modify the sparsity rules" sparse-checkout-err &&
+	test_grep "Disable or modify the sparsity rules" sparse-checkout-err &&
 	test_sparse_unstaged folder1/a &&
 	test_all_match git add --refresh folder1/a &&
 	test_must_be_empty sparse-checkout-err &&
 	test_sparse_unstaged folder1/a &&
 	test_sparse_match test_must_fail git add folder1/new &&
-	grep "Disable or modify the sparsity rules" sparse-checkout-err &&
+	test_grep "Disable or modify the sparsity rules" sparse-checkout-err &&
 	test_sparse_unstaged folder1/new &&
 	test_sparse_match git add --sparse folder1/a &&
 	test_sparse_match git add --sparse folder1/new &&

@@ -661,8 +661,8 @@ test_expect_success 'checkout and reset (mixed)' '
 	# in sparse-checkout or sparse-index.
 	git -C full-checkout reset update-folder1 >full-checkout-out &&
 	test_sparse_match git reset update-folder1 &&
-	grep "M	folder1/a" full-checkout-out &&
-	! grep "M	folder1/a" sparse-checkout-out &&
+	test_grep "M	folder1/a" full-checkout-out &&
+	test_grep ! "M	folder1/a" sparse-checkout-out &&
 	run_on_sparse test_path_is_missing folder1
 '
 

@@ -880,8 +880,8 @@ test_expect_success 'update-index with directories' '
 	# update-index will exit silently when provided with a directory name
 	# containing a trailing slash
 	test_all_match git update-index deep/ folder1/ &&
-	grep "Ignoring path deep/" sparse-checkout-err &&
-	grep "Ignoring path folder1/" sparse-checkout-err &&
+	test_grep "Ignoring path deep/" sparse-checkout-err &&
+	test_grep "Ignoring path folder1/" sparse-checkout-err &&
 
 	# When update-index is given a directory name WITHOUT a trailing slash, it will
 	# behave in different ways depending on the status of the directory on disk:

@@ -1067,7 +1067,7 @@ test_expect_success 'merge with conflict outside cone' '
 
 	# 2. Add the file with conflict markers
 	test_sparse_match test_must_fail git add folder1/a &&
-	grep "Disable or modify the sparsity rules" sparse-checkout-err &&
+	test_grep "Disable or modify the sparsity rules" sparse-checkout-err &&
 	test_sparse_unstaged folder1/a &&
 	test_all_match git add --sparse folder1/a &&
 	test_all_match git status --porcelain=v2 &&

@@ -1076,7 +1076,7 @@ test_expect_success 'merge with conflict outside cone' '
 	#    accept conflict markers as resolved content.
 	run_on_all mv folder2/a folder2/z &&
 	test_sparse_match test_must_fail git add folder2 &&
-	grep "Disable or modify the sparsity rules" sparse-checkout-err &&
+	test_grep "Disable or modify the sparsity rules" sparse-checkout-err &&
 	test_sparse_unstaged folder2/z &&
 	test_all_match git add --sparse folder2 &&
 	test_all_match git status --porcelain=v2 &&

@@ -1107,7 +1107,7 @@ test_expect_success 'cherry-pick/rebase with conflict outside cone' '
 		# SKIP_WORKTREE bit from the index entry for folder1/a, we should
 		# warn that this is a problematic add.
 		test_sparse_match test_must_fail git add folder1/a &&
-		grep "Disable or modify the sparsity rules" sparse-checkout-err &&
+		test_grep "Disable or modify the sparsity rules" sparse-checkout-err &&
 		test_sparse_unstaged folder1/a &&
 		test_all_match git add --sparse folder1/a &&
 		test_all_match git status --porcelain=v2 &&

@@ -1119,7 +1119,7 @@ test_expect_success 'cherry-pick/rebase with conflict outside cone' '
 		# existing index entry with the SKIP_WORKTREE bit cleared.
 		run_on_all mv folder2/a folder2/z &&
 		test_sparse_match test_must_fail git add folder2 &&
-		grep "Disable or modify the sparsity rules" sparse-checkout-err &&
+		test_grep "Disable or modify the sparsity rules" sparse-checkout-err &&
 		test_sparse_unstaged folder2/z &&
 		test_all_match git add --sparse folder2 &&
 		test_all_match git status --porcelain=v2 &&

@@ -1266,7 +1266,7 @@ test_expect_success 'checkout-index with folders' '
 	run_on_all test_must_fail git checkout-index -f -- folder1/ &&
 	test_cmp full-checkout-err sparse-checkout-err &&
 	! test_cmp full-checkout-err sparse-index-err &&
-	grep "is a sparse directory" sparse-index-err
+	test_grep "is a sparse directory" sparse-index-err
 '
 
 test_expect_success 'checkout-index --all' '

@@ -1374,8 +1374,8 @@ test_expect_success 'submodule handling' '
 	# having a submodule prevents "modules" from collapse
 	test_sparse_match git sparse-checkout set deep/deeper1 &&
 	git -C sparse-index ls-files --sparse --stage >cache &&
-	grep "100644 .*	modules/a" cache &&
-	grep "160000 $(git -C initial-repo rev-parse HEAD) 0	modules/sub" cache
+	test_grep "100644 .*	modules/a" cache &&
+	test_grep "160000 $(git -C initial-repo rev-parse HEAD) 0	modules/sub" cache
 '
 
 test_expect_success 'git apply functionality' '

@@ -1392,7 +1392,7 @@ test_expect_success 'git apply functionality' '
 
 	# Apply a patch to a file outside the sparse definition
 	test_sparse_match test_must_fail git apply ../patch-outside &&
-	grep "No such file or directory" sparse-checkout-err &&
+	test_grep "No such file or directory" sparse-checkout-err &&
 
 	# But it works with --index and --cached
 	test_all_match git apply --index --stat ../patch-outside &&

@@ -2013,9 +2013,9 @@ test_expect_success 'mv directory from out-of-cone to in-cone' '
 	test_all_match git status --porcelain=v2 &&
 	test_sparse_match git ls-files -t &&
 	git -C sparse-checkout ls-files -t >actual &&
-	grep -e "H deep/folder1/0/0/0" actual &&
-	grep -e "H deep/folder1/0/1" actual &&
-	grep -e "H deep/folder1/a" actual &&
+	test_grep -e "H deep/folder1/0/0/0" actual &&
+	test_grep -e "H deep/folder1/0/1" actual &&
+	test_grep -e "H deep/folder1/a" actual &&
 
 	test_all_match git reset --hard &&
 

@@ -2025,8 +2025,8 @@ test_expect_success 'mv directory from out-of-cone to in-cone' '
 	test_sparse_match git status --porcelain=v2 &&
 	test_sparse_match git ls-files -t &&
 	git -C sparse-checkout ls-files -t >actual &&
-	grep -e "H deep/0/0/0" actual &&
-	grep -e "H deep/0/1" actual
+	test_grep -e "H deep/0/0/0" actual &&
+	test_grep -e "H deep/0/1" actual
 '
 
 test_expect_success 'rm pathspec inside sparse definition' '

@@ -2517,7 +2517,7 @@ test_expect_success 'advice.sparseIndexExpanded' '
 	mkdir -p sparse-index/deep/deeper2/deepest &&
 	touch sparse-index/deep/deeper2/deepest/bogus &&
 	git -C sparse-index status 2>err &&
-	grep "The sparse index is expanding to a full index" err &&
+	test_grep "The sparse index is expanding to a full index" err &&
 
 	git -C sparse-index sparse-checkout disable 2>err &&
 	test_line_count = 0 err

@@ -856,7 +856,7 @@ test_expect_success 'renaming a section with an overly-long line' '
 		printf "[a] g = h\\n"
 	} >y &&
 	test_must_fail git config ${mode_prefix}rename-section -f y a xyz 2>err &&
-	grep "refusing to work with overly long line in .y. on line 2" err
+	test_grep "refusing to work with overly long line in .y. on line 2" err
 '
 
 cat >> .git/config << EOF

@@ -1671,9 +1671,9 @@ test_expect_success 'git --config-env=key=envvar support' '
 
 test_expect_success 'git --config-env with missing value' '
 	test_must_fail env ENVVAR=value git --config-env 2>error &&
-	grep "no config key given for --config-env" error &&
+	test_grep "no config key given for --config-env" error &&
 	test_must_fail env ENVVAR=value git --config-env config core.name 2>error &&
-	grep "invalid config format: config" error
+	test_grep "invalid config format: config" error
 '
 
 test_expect_success 'git --config-env fails with invalid parameters' '

@@ -2104,7 +2104,7 @@ test_expect_success '--unset last key removes section (except if commented)' '
 	key = true
 	EOF
 	git config ${mode_unset} two.key &&
-	! grep two .git/config &&
+	test_grep ! two .git/config &&
 
 	q_to_tab >.git/config <<-\EOF &&
 	[one]

@@ -2124,7 +2124,7 @@ test_expect_success '--unset last key removes section (except if commented)' '
 	Qkey = true
 	EOF
 	git config ${mode_unset} two.key &&
-	grep two .git/config &&
+	test_grep two .git/config &&
 
 	q_to_tab >.git/config <<-\EOF &&
 	[one]

@@ -2655,7 +2655,7 @@ test_expect_success '--type rejects unknown specifiers' '
 
 test_expect_success '--type=int requires at least one digit' '
 	test_must_fail git config --type int --default m some.key >out 2>error &&
-	grep "bad numeric config value" error &&
+	test_grep "bad numeric config value" error &&
 	test_must_be_empty out
 '
 

@@ -2967,12 +2967,12 @@ test_expect_success 'includeIf.hasconfig:remote.*.url forbids remote url in such
 
 	# test with any Git command
 	test_must_fail git -C hasremoteurlTest status 2>err &&
-	grep "fatal: remote URLs cannot be configured in file directly or indirectly included by includeIf.hasconfig:remote.*.url" err
+	test_grep "fatal: remote URLs cannot be configured in file directly or indirectly included by includeIf.hasconfig:remote.*.url" err
 '
 
 test_expect_success 'negated mode causes failure' '
 	test_must_fail git config --no-get 2>err &&
-	grep "unknown option \`no-get${SQ}" err
+	test_grep "unknown option \`no-get${SQ}" err
 '
 
 test_expect_success 'specifying multiple modes causes failure' '

@@ -353,7 +353,7 @@ test_expect_success 'include cycles are detected' '
 	git -C cycle --git-dir=. config include.path cycle &&
 	git config -f cycle/cycle include.path config &&
 	test_must_fail git -C cycle --git-dir=. config --get-all test.value 2>stderr &&
-	grep "exceeded maximum include depth" stderr
+	test_grep "exceeded maximum include depth" stderr
 '
 
 test_expect_success 'onbranch with unborn branch' '

@@ -180,7 +180,7 @@ test_expect_success 'find integer if value is non parse-able' '
 
 test_expect_success 'non parse-able integer value during iteration' '
 	check_config expect_code 128 git_config_int lamb.head 2>result &&
-	grep "fatal: bad numeric config value .* in file \.git/config" result
+	test_grep "fatal: bad numeric config value .* in file \.git/config" result
 '
 
 test_expect_success 'find bool value for the entered key' '

@@ -302,7 +302,7 @@ test_expect_success 'proper error on directory "files"' '
 	echo "Error (-1) reading configuration file a-directory." >expect &&
 	mkdir a-directory &&
 	test_expect_code 2 test-tool config configset_get_value foo.bar a-directory 2>output &&
-	grep "^warning:" output &&
+	test_grep "^warning:" output &&
 	grep "^Error" output >actual &&
 	test_cmp expect actual
 '

@@ -312,7 +312,7 @@ test_expect_success POSIXPERM,SANITY 'proper error on non-accessible files' '
 	test_when_finished "chmod +r .git/config" &&
 	echo "Error (-1) reading configuration file .git/config." >expect &&
 	test_expect_code 2 test-tool config configset_get_value foo.bar .git/config 2>output &&
-	grep "^warning:" output &&
+	test_grep "^warning:" output &&
 	grep "^Error" output >actual &&
 	test_cmp expect actual
 '

@@ -92,7 +92,7 @@ test_expect_success "deleting current branch adds message to HEAD's log" '
 	git update-ref -m delete-$m -d $m &&
 	test_must_fail git show-ref --verify -q $m &&
 	test-tool ref-store main for-each-reflog-ent HEAD >actual &&
-	grep "delete-$m$" actual
+	test_grep "delete-$m$" actual
 '
 
 test_expect_success "deleting by HEAD adds message to HEAD's log" '

@@ -102,7 +102,7 @@ test_expect_success "deleting by HEAD adds message to HEAD's log" '
 	git update-ref -m delete-by-head -d HEAD &&
 	test_must_fail git show-ref --verify -q $m &&
 	test-tool ref-store main for-each-reflog-ent HEAD >actual &&
-	grep "delete-by-head$" actual
+	test_grep "delete-by-head$" actual
 '
 
 test_expect_success 'update-ref does not create reflogs by default' '

@@ -192,7 +192,10 @@ test_expect_success "move $m (by HEAD)" '
 test_expect_success "delete $m (by HEAD) should remove both packed and loose $m" '
 	test_when_finished "git update-ref -d $m" &&
 	git update-ref -d HEAD $B &&
-	! grep "$m" .git/packed-refs &&
+	if test_have_prereq REFFILES
+	then
+		test_grep ! "$m" .git/packed-refs
+	fi &&
 	test_must_fail git show-ref --verify -q $m
 '
 

@@ -575,103 +578,103 @@ test_expect_success 'stdin works with no input' '
 test_expect_success 'stdin fails on empty line' '
 	echo "" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: empty command in input" err
+	test_grep "fatal: empty command in input" err
 '
 
 test_expect_success 'stdin fails on only whitespace' '
 	echo " " >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: whitespace before command:  " err
+	test_grep "fatal: whitespace before command:  " err
 '
 
 test_expect_success 'stdin fails on leading whitespace' '
 	echo " create $a $m" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: whitespace before command:  create $a $m" err
+	test_grep "fatal: whitespace before command:  create $a $m" err
 '
 
 test_expect_success 'stdin fails on unknown command' '
 	echo "unknown $a" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: unknown command: unknown $a" err
+	test_grep "fatal: unknown command: unknown $a" err
 '
 
 test_expect_success 'stdin fails on unbalanced quotes' '
 	echo "create $a \"main" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: badly quoted argument: \\\"main" err
+	test_grep "fatal: badly quoted argument: \\\"main" err
 '
 
 test_expect_success 'stdin fails on invalid escape' '
 	echo "create $a \"ma\zn\"" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: badly quoted argument: \\\"ma\\\\zn\\\"" err
+	test_grep "fatal: badly quoted argument: \\\"ma\\\\zn\\\"" err
 '
 
 test_expect_success 'stdin fails on junk after quoted argument' '
 	echo "create \"$a\"main" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: unexpected character after quoted argument: \\\"$a\\\"main" err
+	test_grep "fatal: unexpected character after quoted argument: \\\"$a\\\"main" err
 '
 
 test_expect_success 'stdin fails create with no ref' '
 	echo "create " >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: create: missing <ref>" err
+	test_grep "fatal: create: missing <ref>" err
 '
 
 test_expect_success 'stdin fails create with no new value' '
 	echo "create $a" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: create $a: missing <new-oid>" err
+	test_grep "fatal: create $a: missing <new-oid>" err
 '
 
 test_expect_success 'stdin fails create with too many arguments' '
 	echo "create $a $m $m" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: create $a: extra input:  $m" err
+	test_grep "fatal: create $a: extra input:  $m" err
 '
 
 test_expect_success 'stdin fails update with no ref' '
 	echo "update " >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: update: missing <ref>" err
+	test_grep "fatal: update: missing <ref>" err
 '
 
 test_expect_success 'stdin fails update with no new value' '
 	echo "update $a" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: update $a: missing <new-oid>" err
+	test_grep "fatal: update $a: missing <new-oid>" err
 '
 
 test_expect_success 'stdin fails update with too many arguments' '
 	echo "update $a $m $m $m" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: update $a: extra input:  $m" err
+	test_grep "fatal: update $a: extra input:  $m" err
 '
 
 test_expect_success 'stdin fails delete with no ref' '
 	echo "delete " >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: delete: missing <ref>" err
+	test_grep "fatal: delete: missing <ref>" err
 '
 
 test_expect_success 'stdin fails delete with too many arguments' '
 	echo "delete $a $m $m" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: delete $a: extra input:  $m" err
+	test_grep "fatal: delete $a: extra input:  $m" err
 '
 
 test_expect_success 'stdin fails verify with too many arguments' '
 	echo "verify $a $m $m" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: verify $a: extra input:  $m" err
+	test_grep "fatal: verify $a: extra input:  $m" err
 '
 
 test_expect_success 'stdin fails option with unknown name' '
 	echo "option unknown" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: option unknown: unknown" err
+	test_grep "fatal: option unknown: unknown" err
 '
 
 test_expect_success 'stdin fails with duplicate refs' '

@@ -759,28 +762,28 @@ test_expect_success 'stdin create ref works with path with space to blob' '
 test_expect_success 'stdin update ref fails with wrong old value' '
 	echo "update $c $m $m~1" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: cannot lock ref '"'"'$c'"'"'" err &&
+	test_grep "fatal: cannot lock ref '"'"'$c'"'"'" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 
 test_expect_success 'stdin update ref fails with bad old value' '
 	echo "update $c $m does-not-exist" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: update $c: invalid <old-oid>: does-not-exist" err &&
+	test_grep "fatal: update $c: invalid <old-oid>: does-not-exist" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 
 test_expect_success 'stdin create ref fails with bad new value' '
 	echo "create $c does-not-exist" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: create $c: invalid <new-oid>: does-not-exist" err &&
+	test_grep "fatal: create $c: invalid <new-oid>: does-not-exist" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 
 test_expect_success 'stdin create ref fails with zero new value' '
 	echo "create $c " >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: create $c: zero <new-oid>" err &&
+	test_grep "fatal: create $c: zero <new-oid>" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 

@@ -795,7 +798,7 @@ test_expect_success 'stdin update ref works with right old value' '
 test_expect_success 'stdin delete ref fails with wrong old value' '
 	echo "delete $a $m~1" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: cannot lock ref '"'"'$a'"'"'" err &&
+	test_grep "fatal: cannot lock ref '"'"'$a'"'"'" err &&
 	git rev-parse $m >expect &&
 	git rev-parse $a >actual &&
 	test_cmp expect actual

@@ -804,7 +807,7 @@ test_expect_success 'stdin delete ref fails with wrong old value' '
 test_expect_success 'stdin delete ref fails with zero old value' '
 	echo "delete $a " >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: delete $a: zero <old-oid>" err &&
+	test_grep "fatal: delete $a: zero <old-oid>" err &&
 	git rev-parse $m >expect &&
 	git rev-parse $a >actual &&
 	test_cmp expect actual

@@ -965,7 +968,7 @@ test_expect_success 'stdin update refs fails with wrong old value' '
 	update $c  ''
 	EOF
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: cannot lock ref '"'"'$c'"'"'" err &&
+	test_grep "fatal: cannot lock ref '"'"'$c'"'"'" err &&
 	git rev-parse $m >expect &&
 	git rev-parse $a >actual &&
 	test_cmp expect actual &&

@@ -998,123 +1001,123 @@ test_expect_success 'stdin -z works on empty input' '
 test_expect_success 'stdin -z fails on empty line' '
 	echo "" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: whitespace before command: " err
+	test_grep "fatal: whitespace before command: " err
 '
 
 test_expect_success 'stdin -z fails on empty command' '
 	printf $F "" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: empty command in input" err
+	test_grep "fatal: empty command in input" err
 '
 
 test_expect_success 'stdin -z fails on only whitespace' '
 	printf $F " " >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: whitespace before command:  " err
+	test_grep "fatal: whitespace before command:  " err
 '
 
 test_expect_success 'stdin -z fails on leading whitespace' '
 	printf $F " create $a" "$m" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: whitespace before command:  create $a" err
+	test_grep "fatal: whitespace before command:  create $a" err
 '
 
 test_expect_success 'stdin -z fails on unknown command' '
 	printf $F "unknown $a" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: unknown command: unknown $a" err
+	test_grep "fatal: unknown command: unknown $a" err
 '
 
 test_expect_success 'stdin -z fails create with no ref' '
 	printf $F "create " >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: create: missing <ref>" err
+	test_grep "fatal: create: missing <ref>" err
 '
 
 test_expect_success 'stdin -z fails create with no new value' '
 	printf $F "create $a" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: create $a: unexpected end of input when reading <new-oid>" err
+	test_grep "fatal: create $a: unexpected end of input when reading <new-oid>" err
 '
 
 test_expect_success 'stdin -z fails create with too many arguments' '
 	printf $F "create $a" "$m" "$m" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: unknown command: $m" err
+	test_grep "fatal: unknown command: $m" err
 '
 
 test_expect_success 'stdin -z fails update with no ref' '
 	printf $F "update " >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: update: missing <ref>" err
+	test_grep "fatal: update: missing <ref>" err
 '
 
 test_expect_success 'stdin -z fails update with too few args' '
 	printf $F "update $a" "$m" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: update $a: unexpected end of input when reading <old-oid>" err
+	test_grep "fatal: update $a: unexpected end of input when reading <old-oid>" err
 '
 
 test_expect_success 'stdin -z emits warning with empty new value' '
 	git update-ref $a $m &&
 	printf $F "update $a" "" "" >stdin &&
 	git update-ref -z --stdin <stdin 2>err &&
-	grep "warning: update $a: missing <new-oid>, treating as zero" err &&
+	test_grep "warning: update $a: missing <new-oid>, treating as zero" err &&
 	test_must_fail git rev-parse --verify -q $a
 '
 
 test_expect_success 'stdin -z fails update with no new value' '
 	printf $F "update $a" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: update $a: unexpected end of input when reading <new-oid>" err
+	test_grep "fatal: update $a: unexpected end of input when reading <new-oid>" err
 '
 
 test_expect_success 'stdin -z fails update with no old value' '
 	printf $F "update $a" "$m" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: update $a: unexpected end of input when reading <old-oid>" err
+	test_grep "fatal: update $a: unexpected end of input when reading <old-oid>" err
 '
 
 test_expect_success 'stdin -z fails update with too many arguments' '
 	printf $F "update $a" "$m" "$m" "$m" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: unknown command: $m" err
+	test_grep "fatal: unknown command: $m" err
 '
 
 test_expect_success 'stdin -z fails delete with no ref' '
 	printf $F "delete " >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: delete: missing <ref>" err
+	test_grep "fatal: delete: missing <ref>" err
 '
 
 test_expect_success 'stdin -z fails delete with no old value' '
 	printf $F "delete $a" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: delete $a: unexpected end of input when reading <old-oid>" err
+	test_grep "fatal: delete $a: unexpected end of input when reading <old-oid>" err
 '
 
 test_expect_success 'stdin -z fails delete with too many arguments' '
 	printf $F "delete $a" "$m" "$m" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: unknown command: $m" err
+	test_grep "fatal: unknown command: $m" err
 '
 
 test_expect_success 'stdin -z fails verify with too many arguments' '
 	printf $F "verify $a" "$m" "$m" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: unknown command: $m" err
+	test_grep "fatal: unknown command: $m" err
 '
 
 test_expect_success 'stdin -z fails verify with no old value' '
 	printf $F "verify $a" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: verify $a: unexpected end of input when reading <old-oid>" err
+	test_grep "fatal: verify $a: unexpected end of input when reading <old-oid>" err
 '
 
 test_expect_success 'stdin -z fails option with unknown name' '
 	printf $F "option unknown" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: option unknown: unknown" err
+	test_grep "fatal: option unknown: unknown" err
 '
 
 test_expect_success 'stdin -z fails with duplicate refs' '

@@ -1160,14 +1163,14 @@ test_expect_success 'stdin -z create ref works with path with space to blob' '
 test_expect_success 'stdin -z update ref fails with wrong old value' '
 	printf $F "update $c" "$m" "$m~1" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: cannot lock ref '"'"'$c'"'"'" err &&
+	test_grep "fatal: cannot lock ref '"'"'$c'"'"'" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 
 test_expect_success 'stdin -z update ref fails with bad old value' '
 	printf $F "update $c" "$m" "does-not-exist" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: update $c: invalid <old-oid>: does-not-exist" err &&
+	test_grep "fatal: update $c: invalid <old-oid>: does-not-exist" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 

@@ -1176,7 +1179,7 @@ test_expect_success 'stdin -z create ref fails when ref exists' '
 	git rev-parse "$c" >expect &&
 	printf $F "create $c" "$m~1" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: cannot lock ref '"'"'$c'"'"'" err &&
+	test_grep "fatal: cannot lock ref '"'"'$c'"'"'" err &&
 	git rev-parse "$c" >actual &&
 	test_cmp expect actual
 '

@@ -1185,28 +1188,28 @@ test_expect_success 'stdin -z create ref fails with bad new value' '
 	git update-ref -d "$c" &&
 	printf $F "create $c" "does-not-exist" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: create $c: invalid <new-oid>: does-not-exist" err &&
+	test_grep "fatal: create $c: invalid <new-oid>: does-not-exist" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 
 test_expect_success 'stdin -z create ref fails with empty new value' '
 	printf $F "create $c" "" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: create $c: missing <new-oid>" err &&
+	test_grep "fatal: create $c: missing <new-oid>" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 
 test_expect_success 'stdin -z create ref fails with non commit object' '
 	printf $F "create $c" "$(test_oid 001)" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: trying to write ref ${SQ}$c${SQ} with nonexistent object" err &&
+	test_grep "fatal: trying to write ref ${SQ}$c${SQ} with nonexistent object" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 
 test_expect_success 'stdin -z update ref fails with non commit object' '
 	printf $F "update $b" "$(test_oid 001)" "" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: trying to write ref ${SQ}$b${SQ} with nonexistent object" err &&
+	test_grep "fatal: trying to write ref ${SQ}$b${SQ} with nonexistent object" err &&
 	test_must_fail git rev-parse --verify -q $c
 '
 

@@ -1221,7 +1224,7 @@ test_expect_success 'stdin -z update ref works with right old value' '
 test_expect_success 'stdin -z delete ref fails with wrong old value' '
 	printf $F "delete $a" "$m~1" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: cannot lock ref '"'"'$a'"'"'" err &&
+	test_grep "fatal: cannot lock ref '"'"'$a'"'"'" err &&
 	git rev-parse $m >expect &&
 	git rev-parse $a >actual &&
 	test_cmp expect actual

@@ -1230,7 +1233,7 @@ test_expect_success 'stdin -z delete ref fails with wrong old value' '
 test_expect_success 'stdin -z delete ref fails with zero old value' '
 	printf $F "delete $a" "$Z" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: delete $a: zero <old-oid>" err &&
+	test_grep "fatal: delete $a: zero <old-oid>" err &&
 	git rev-parse $m >expect &&
 	git rev-parse $a >actual &&
 	test_cmp expect actual

@@ -1336,7 +1339,7 @@ test_expect_success 'stdin -z update refs fails with wrong old value' '
 	git update-ref $c $m &&
 	printf $F "update $a" "$m" "$m" "update $b" "$m" "$m" "update $c" "$m" "$Z" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: cannot lock ref '"'"'$c'"'"'" err &&
+	test_grep "fatal: cannot lock ref '"'"'$c'"'"'" err &&
 	git rev-parse $m >expect &&
 	git rev-parse $a >actual &&
 	test_cmp expect actual &&

@@ -1415,13 +1418,13 @@ test_expect_success 'handle per-worktree refs in refs/bisect' '
 		cd worktree &&
 		git commit --allow-empty -m "test commit"  &&
 		git for-each-ref >for-each-ref.out &&
-		! grep refs/bisect for-each-ref.out &&
+		test_grep ! refs/bisect for-each-ref.out &&
 		git update-ref refs/bisect/something HEAD &&
 		git rev-parse refs/bisect/something >../worktree-head &&
 		git for-each-ref | grep refs/bisect/something
 	) &&
 	git show-ref >actual &&
-	! grep 'refs/bisect' actual &&
+	test_grep ! 'refs/bisect' actual &&
 	test_must_fail git rev-parse refs/bisect/something &&
 	git update-ref refs/bisect/something HEAD &&
 	git rev-parse refs/bisect/something >main-head &&

@@ -1477,7 +1480,7 @@ test_expect_success 'transaction exits on multiple aborts' '
 	test_must_fail git update-ref --stdin <stdin >actual 2>err &&
 	printf "%s: ok\n" abort >expect &&
 	test_cmp expect actual &&
-	grep "fatal: transaction is closed" err
+	test_grep "fatal: transaction is closed" err
 '
 
 test_expect_success 'transaction exits on start after prepare' '

@@ -1488,7 +1491,7 @@ test_expect_success 'transaction exits on start after prepare' '
 	test_must_fail git update-ref --stdin <stdin 2>err >actual &&
 	printf "%s: ok\n" prepare >expect &&
 	test_cmp expect actual &&
-	grep "fatal: prepared transactions can only be closed" err
+	test_grep "fatal: prepared transactions can only be closed" err
 '
 
 test_expect_success 'transaction handles empty abort with missing prepare' '

@@ -1649,7 +1652,7 @@ test_expect_success PIPE 'transaction flushes status updates' '
 
 	# This must now fail given that we have locked the ref.
 	test_must_fail git update-ref refs/heads/flush $B 2>stderr &&
-	grep "fatal: update_ref failed for ref ${SQ}refs/heads/flush${SQ}: cannot lock ref" stderr &&
+	test_grep "fatal: update_ref failed for ref ${SQ}refs/heads/flush${SQ}: cannot lock ref" stderr &&
 
 	echo commit >&9 &&
 	echo "commit: ok" >expected &&

@@ -1675,7 +1678,7 @@ do
 		git symbolic-ref refs/heads/symref $a &&
 		format_command $type "symref-verify refs/heads/symref" "$a" >stdin &&
 		test_must_fail git update-ref --stdin $type <stdin 2>err &&
-		grep "fatal: symref-verify: cannot operate with deref mode" err
+		test_grep "fatal: symref-verify: cannot operate with deref mode" err
 	'
 
 	test_expect_success "stdin $type symref-verify fails with too many arguments" '

@@ -1683,9 +1686,9 @@ do
 		test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err  &&
 		if test "$type" = "-z"
 		then
-			grep "fatal: unknown command: $a" err
+			test_grep "fatal: unknown command: $a" err
 		else
-			grep "fatal: symref-verify refs/heads/symref: extra input:  $a" err
+			test_grep "fatal: symref-verify refs/heads/symref: extra input:  $a" err
 		fi
 	'
 

@@ -1718,7 +1721,7 @@ do
 		test-tool ref-store main for-each-reflog-ent refs/heads/symref >before &&
 		format_command $type "symref-verify refs/heads/missing" "refs/heads/unknown" >stdin &&
 		test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err &&
-		grep "fatal: cannot lock ref ${SQ}refs/heads/missing${SQ}: unable to resolve reference ${SQ}refs/heads/missing${SQ}" err &&
+		test_grep "fatal: cannot lock ref ${SQ}refs/heads/missing${SQ}: unable to resolve reference ${SQ}refs/heads/missing${SQ}" err &&
 		test_must_fail git rev-parse --verify -q refs/heads/missing &&
 		test-tool ref-store main for-each-reflog-ent refs/heads/symref >after &&
 		test_cmp before after

@@ -1744,13 +1747,13 @@ do
 		git symbolic-ref refs/heads/symref $a &&
 		format_command $type "symref-delete refs/heads/symref" "$a" >stdin &&
 		test_must_fail git update-ref --stdin $type <stdin 2>err &&
-		grep "fatal: symref-delete: cannot operate with deref mode" err
+		test_grep "fatal: symref-delete: cannot operate with deref mode" err
 	'
 
 	test_expect_success "stdin $type symref-delete fails with no ref" '
 		format_command $type "symref-delete " >stdin &&
 		test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err &&
-		grep "fatal: symref-delete: missing <ref>" err
+		test_grep "fatal: symref-delete: missing <ref>" err
 	'
 
 	test_expect_success "stdin $type symref-delete fails deleting regular ref" '

@@ -1758,7 +1761,7 @@ do
 		git update-ref refs/heads/regularref $a &&
 		format_command $type "symref-delete refs/heads/regularref" "$a" >stdin &&
 		test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err &&
-		grep "fatal: cannot lock ref ${SQ}refs/heads/regularref${SQ}: expected symref with target ${SQ}$a${SQ}: but is a regular ref" err
+		test_grep "fatal: cannot lock ref ${SQ}refs/heads/regularref${SQ}: expected symref with target ${SQ}$a${SQ}: but is a regular ref" err
 	'
 
 	test_expect_success "stdin $type symref-delete fails with too many arguments" '

@@ -1766,16 +1769,16 @@ do
 		test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err &&
 		if test "$type" = "-z"
 		then
-			grep "fatal: unknown command: $a" err
+			test_grep "fatal: unknown command: $a" err
 		else
-			grep "fatal: symref-delete refs/heads/symref: extra input:  $a" err
+			test_grep "fatal: symref-delete refs/heads/symref: extra input:  $a" err
 		fi
 	'
 
 	test_expect_success "stdin $type symref-delete fails with wrong old value" '
 		format_command $type "symref-delete refs/heads/symref" "$m" >stdin &&
 		test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err &&
-		grep "fatal: verifying symref target: ${SQ}refs/heads/symref${SQ}: is at $a but expected refs/heads/main" err &&
+		test_grep "fatal: verifying symref target: ${SQ}refs/heads/symref${SQ}: is at $a but expected refs/heads/main" err &&
 		git symbolic-ref refs/heads/symref >expect &&
 		echo $a >actual &&
 		test_cmp expect actual

@@ -1813,9 +1816,9 @@ do
 		test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err &&
 		if test "$type" = "-z"
 		then
-			grep "fatal: unknown command: $a" err
+			test_grep "fatal: unknown command: $a" err
 		else
-			grep "fatal: symref-create refs/heads/symref: extra input:  $a" err
+			test_grep "fatal: symref-create refs/heads/symref: extra input:  $a" err
 		fi
 	'
 

@@ -1878,16 +1881,16 @@ do
 		test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err &&
 		if test "$type" = "-z"
 		then
-			grep "fatal: unknown command: $a" err
+			test_grep "fatal: unknown command: $a" err
 		else
-			grep "fatal: symref-update refs/heads/symref: extra input:  $a" err
+			test_grep "fatal: symref-update refs/heads/symref: extra input:  $a" err
 		fi
 	'
 
 	test_expect_success "stdin $type symref-update fails with wrong old value argument" '
 		format_command $type "symref-update refs/heads/symref" "$a" "foo" "$a" "$a" >stdin &&
 		test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err &&
-		grep "fatal: symref-update refs/heads/symref: invalid arg ${SQ}foo${SQ} for old value" err
+		test_grep "fatal: symref-update refs/heads/symref: invalid arg ${SQ}foo${SQ} for old value" err
 	'
 
 	test_expect_success "stdin $type symref-update creates with zero old value" '

@@ -1923,7 +1926,7 @@ do
 		git symbolic-ref refs/heads/symref $a &&
 		format_command $type "symref-update refs/heads/symref" "$m" "ref" "$b" >stdin &&
 		test_must_fail git update-ref --stdin $type --no-deref <stdin 2>err &&
-		grep "fatal: verifying symref target: ${SQ}refs/heads/symref${SQ}: is at $a but expected $b" err &&
+		test_grep "fatal: verifying symref target: ${SQ}refs/heads/symref${SQ}: is at $a but expected $b" err &&
 		test_must_fail git rev-parse --verify -q $c
 	'
 

@@ -1998,7 +2001,7 @@ do
 		git symbolic-ref --no-recurse refs/heads/symref >actual &&
 		test_cmp expect actual &&
 		test-tool ref-store main for-each-reflog-ent refs/heads/symref >actual &&
-		grep "$Z $(git rev-parse $a)" actual
+		test_grep "$Z $(git rev-parse $a)" actual
 	'
 
 	test_expect_success "stdin $type symref-update regular ref to symref with correct old-oid" '

@@ -2010,7 +2013,7 @@ do
 		git symbolic-ref --no-recurse refs/heads/regularref >actual &&
 		test_cmp expect actual &&
 		test-tool ref-store main for-each-reflog-ent refs/heads/regularref >actual &&
-		grep "$(git rev-parse $a) $(git rev-parse $a)" actual
+		test_grep "$(git rev-parse $a) $(git rev-parse $a)" actual
 	'
 
 	test_expect_success "stdin $type symref-update regular ref to symref fails with wrong old-oid" '

@@ -2018,7 +2021,7 @@ do
 		git update-ref --no-deref refs/heads/regularref $a &&
 		format_command $type "symref-update refs/heads/regularref" "$a" "oid" "$(git rev-parse refs/heads/target2)" >stdin &&
 		test_must_fail git update-ref --stdin $type <stdin 2>err &&
-		grep "fatal: cannot lock ref ${SQ}refs/heads/regularref${SQ}: is at $(git rev-parse $a) but expected $(git rev-parse refs/heads/target2)" err &&
+		test_grep "fatal: cannot lock ref ${SQ}refs/heads/regularref${SQ}: is at $(git rev-parse $a) but expected $(git rev-parse refs/heads/target2)" err &&
 		echo $(git rev-parse $a) >expect &&
 		git rev-parse refs/heads/regularref >actual &&
 		test_cmp expect actual

@@ -2029,7 +2032,7 @@ do
 		git update-ref --no-deref refs/heads/regularref $a &&
 		format_command $type "symref-update refs/heads/regularref" "$a" "oid" "not-a-ref-oid" >stdin &&
 		test_must_fail git update-ref --stdin $type <stdin 2>err &&
-		grep "fatal: symref-update refs/heads/regularref: invalid oid: not-a-ref-oid" err &&
+		test_grep "fatal: symref-update refs/heads/regularref: invalid oid: not-a-ref-oid" err &&
 		echo $(git rev-parse $a) >expect &&
 		git rev-parse refs/heads/regularref >actual &&
 		test_cmp expect actual

@@ -2040,7 +2043,7 @@ do
 		git symbolic-ref refs/heads/symref refs/heads/target2 &&
 		format_command $type "symref-update refs/heads/symref" "$a" "oid" "$Z" >stdin &&
 		test_must_fail git update-ref --stdin $type <stdin 2>err &&
-		grep "fatal: cannot lock ref ${SQ}refs/heads/symref${SQ}: reference already exists" err &&
+		test_grep "fatal: cannot lock ref ${SQ}refs/heads/symref${SQ}: reference already exists" err &&
 		echo refs/heads/target2 >expect &&
 		git symbolic-ref refs/heads/symref >actual &&
 		test_cmp expect actual

@@ -2060,7 +2063,7 @@ do
 		git symbolic-ref --no-recurse refs/heads/symref >actual &&
 		test_cmp expect actual &&
 		test-tool ref-store main for-each-reflog-ent refs/heads/symref >actual &&
-		grep "$(git rev-parse $a) $(git rev-parse $a)" actual
+		test_grep "$(git rev-parse $a) $(git rev-parse $a)" actual
 	'
 
 	test_expect_success "stdin $type symref-update regular ref to symref" '

@@ -2072,7 +2075,7 @@ do
 		git symbolic-ref --no-recurse refs/heads/regularref >actual &&
 		test_cmp expect actual &&
 		test-tool ref-store main for-each-reflog-ent refs/heads/regularref >actual &&
-		grep "$(git rev-parse $a) $(git rev-parse $a)" actual
+		test_grep "$(git rev-parse $a) $(git rev-parse $a)" actual
 	'
 
 	test_expect_success "stdin $type batch-updates" '

@@ -213,19 +213,19 @@ test_expect_success 'show-ref --verify with dangling ref' '
 
 test_expect_success 'show-ref sub-modes are mutually exclusive' '
 	test_must_fail git show-ref --verify --exclude-existing 2>err &&
-	grep "verify" err &&
-	grep "exclude-existing" err &&
-	grep "cannot be used together" err &&
+	test_grep "verify" err &&
+	test_grep "exclude-existing" err &&
+	test_grep "cannot be used together" err &&
 
 	test_must_fail git show-ref --verify --exists 2>err &&
-	grep "verify" err &&
-	grep "exists" err &&
-	grep "cannot be used together" err &&
+	test_grep "verify" err &&
+	test_grep "exists" err &&
+	test_grep "cannot be used together" err &&
 
 	test_must_fail git show-ref --exclude-existing --exists 2>err &&
-	grep "exclude-existing" err &&
-	grep "exists" err &&
-	grep "cannot be used together" err
+	test_grep "exclude-existing" err &&
+	test_grep "exists" err &&
+	test_grep "cannot be used together" err
 '
 
 test_done

@@ -108,12 +108,12 @@ test_expect_success setup '
 
 test_expect_success 'correct usage on sub-command -h' '
 	test_expect_code 129 git reflog expire -h >err &&
-	grep "git reflog expire" err
+	test_grep "git reflog expire" err
 '
 
 test_expect_success 'correct usage on "git reflog show -h"' '
 	test_expect_code 129 git reflog show -h >err &&
-	grep -F "git reflog [show]" err
+	test_grep -F "git reflog [show]" err
 '
 
 test_expect_success 'pass through -- to sub-command' '

@@ -32,7 +32,7 @@ test_expect_success 'ambiguous main-worktree/HEAD' '
 	test_when_finished git update-ref -d refs/heads/main-worktree/HEAD &&
 	git update-ref refs/heads/main-worktree/HEAD $(git rev-parse HEAD) &&
 	git rev-parse main-worktree/HEAD 2>warn &&
-	grep "main-worktree/HEAD.*ambiguous" warn
+	test_grep "main-worktree/HEAD.*ambiguous" warn
 '
 
 test_expect_success 'resolve worktrees/xx/HEAD' '

@@ -45,7 +45,7 @@ test_expect_success 'ambiguous worktrees/xx/HEAD' '
 	git update-ref refs/heads/worktrees/wt1/HEAD $(git rev-parse HEAD) &&
 	test_when_finished git update-ref -d refs/heads/worktrees/wt1/HEAD &&
 	git rev-parse worktrees/wt1/HEAD 2>warn &&
-	grep "worktrees/wt1/HEAD.*ambiguous" warn
+	test_grep "worktrees/wt1/HEAD.*ambiguous" warn
 '
 
 test_expect_success 'reflog of main-worktree/HEAD' '

@@ -47,7 +47,7 @@ test_expect_success 'git branch shows badly named ref as warning' '
 	test_when_finished "test-tool ref-store main delete-refs REF_NO_DEREF msg refs/heads/broken...ref" &&
 	git branch >output 2>error &&
 	test_grep -e "ignoring ref with broken name refs/heads/broken\.\.\.ref" error &&
-	! grep -e "broken\.\.\.ref" output
+	test_grep ! -e "broken\.\.\.ref" output
 '
 
 test_expect_success 'branch -d can delete badly named ref' '

@@ -55,8 +55,8 @@ test_expect_success 'branch -d can delete badly named ref' '
 	test_when_finished "test-tool ref-store main delete-refs REF_NO_DEREF msg refs/heads/broken...ref" &&
 	git branch -d broken...ref &&
 	git branch >output 2>error &&
-	! grep -e "broken\.\.\.ref" error &&
-	! grep -e "broken\.\.\.ref" output
+	test_grep ! -e "broken\.\.\.ref" error &&
+	test_grep ! -e "broken\.\.\.ref" output
 '
 
 test_expect_success 'branch -D can delete badly named ref' '

@@ -64,8 +64,8 @@ test_expect_success 'branch -D can delete badly named ref' '
 	test_when_finished "test-tool ref-store main delete-refs REF_NO_DEREF msg refs/heads/broken...ref" &&
 	git branch -D broken...ref &&
 	git branch >output 2>error &&
-	! grep -e "broken\.\.\.ref" error &&
-	! grep -e "broken\.\.\.ref" output
+	test_grep ! -e "broken\.\.\.ref" error &&
+	test_grep ! -e "broken\.\.\.ref" output
 '
 
 test_expect_success 'branch -D cannot delete non-ref in .git dir' '

@@ -93,8 +93,8 @@ test_expect_success 'git branch cannot create a badly named ref' '
 	test_when_finished "test-tool ref-store main delete-refs REF_NO_DEREF msg refs/heads/broken...ref" &&
 	test_must_fail git branch broken...ref &&
 	git branch >output 2>error &&
-	! grep -e "broken\.\.\.ref" error &&
-	! grep -e "broken\.\.\.ref" output
+	test_grep ! -e "broken\.\.\.ref" error &&
+	test_grep ! -e "broken\.\.\.ref" output
 '
 
 test_expect_success 'branch -m cannot rename to a bad ref name' '

@@ -104,8 +104,8 @@ test_expect_success 'branch -m cannot rename to a bad ref name' '
 	test_must_fail git branch -m goodref broken...ref &&
 	test_cmp_rev main goodref &&
 	git branch >output 2>error &&
-	! grep -e "broken\.\.\.ref" error &&
-	! grep -e "broken\.\.\.ref" output
+	test_grep ! -e "broken\.\.\.ref" error &&
+	test_grep ! -e "broken\.\.\.ref" output
 '
 
 test_expect_failure 'branch -m can rename from a bad ref name' '

@@ -115,16 +115,16 @@ test_expect_failure 'branch -m can rename from a bad ref name' '
 	git branch -m broken...ref renamed &&
 	test_cmp_rev main renamed &&
 	git branch >output 2>error &&
-	! grep -e "broken\.\.\.ref" error &&
-	! grep -e "broken\.\.\.ref" output
+	test_grep ! -e "broken\.\.\.ref" error &&
+	test_grep ! -e "broken\.\.\.ref" output
 '
 
 test_expect_success 'push cannot create a badly named ref' '
 	test_when_finished "test-tool ref-store main delete-refs REF_NO_DEREF msg refs/heads/broken...ref" &&
 	test_must_fail git push "file://$(pwd)" HEAD:refs/heads/broken...ref &&
 	git branch >output 2>error &&
-	! grep -e "broken\.\.\.ref" error &&
-	! grep -e "broken\.\.\.ref" output
+	test_grep ! -e "broken\.\.\.ref" error &&
+	test_grep ! -e "broken\.\.\.ref" output
 '
 
 test_expect_failure 'push --mirror can delete badly named ref' '

@@ -144,8 +144,8 @@ test_expect_failure 'push --mirror can delete badly named ref' '
 	) &&
 	git -C src push --mirror "file://$top/dest" &&
 	git -C dest branch >output 2>error &&
-	! grep -e "broken\.\.\.ref" error &&
-	! grep -e "broken\.\.\.ref" output
+	test_grep ! -e "broken\.\.\.ref" error &&
+	test_grep ! -e "broken\.\.\.ref" output
 '
 
 test_expect_success 'rev-parse skips symref pointing to broken name' '

@@ -168,9 +168,9 @@ test_expect_success 'for-each-ref emits warnings for broken names' '
 	test-tool ref-store main create-symref refs/heads/broken...symref refs/heads/main &&
 	test_when_finished "test-tool ref-store main delete-refs REF_NO_DEREF msg refs/heads/broken...symref" &&
 	git for-each-ref >output 2>error &&
-	! grep -e "broken\.\.\.ref" output &&
-	! grep -e "badname" output &&
-	! grep -e "broken\.\.\.symref" output &&
+	test_grep ! -e "broken\.\.\.ref" output &&
+	test_grep ! -e "badname" output &&
+	test_grep ! -e "broken\.\.\.symref" output &&
 	test_grep "ignoring ref with broken name refs/heads/broken\.\.\.ref" error &&
 	test_grep ! "ignoring broken ref refs/heads/badname" error &&
 	test_grep "ignoring ref with broken name refs/heads/broken\.\.\.symref" error

@@ -183,8 +183,8 @@ test_expect_success 'update-ref -d can delete broken name' '
 	test_must_be_empty output &&
 	test_must_be_empty error &&
 	git branch >output 2>error &&
-	! grep -e "broken\.\.\.ref" error &&
-	! grep -e "broken\.\.\.ref" output
+	test_grep ! -e "broken\.\.\.ref" error &&
+	test_grep ! -e "broken\.\.\.ref" output
 '
 
 test_expect_success 'branch -d can delete broken name' '

@@ -194,8 +194,8 @@ test_expect_success 'branch -d can delete broken name' '
 	test_grep "Deleted branch broken...ref (was broken)" output &&
 	test_must_be_empty error &&
 	git branch >output 2>error &&
-	! grep -e "broken\.\.\.ref" error &&
-	! grep -e "broken\.\.\.ref" output
+	test_grep ! -e "broken\.\.\.ref" error &&
+	test_grep ! -e "broken\.\.\.ref" output
 '
 
 test_expect_success 'update-ref --no-deref -d can delete symref to broken name' '

@@ -313,37 +313,37 @@ test_expect_success 'update-ref -d cannot delete absolute path' '
 test_expect_success 'update-ref --stdin fails create with bad ref name' '
 	echo "create ~a refs/heads/main" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: invalid ref format: ~a" err
+	test_grep "fatal: invalid ref format: ~a" err
 '
 
 test_expect_success 'update-ref --stdin fails update with bad ref name' '
 	echo "update ~a refs/heads/main" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: invalid ref format: ~a" err
+	test_grep "fatal: invalid ref format: ~a" err
 '
 
 test_expect_success 'update-ref --stdin fails delete with bad ref name' '
 	echo "delete ~a refs/heads/main" >stdin &&
 	test_must_fail git update-ref --stdin <stdin 2>err &&
-	grep "fatal: invalid ref format: ~a" err
+	test_grep "fatal: invalid ref format: ~a" err
 '
 
 test_expect_success 'update-ref --stdin -z fails create with bad ref name' '
 	printf "%s\0" "create ~a " refs/heads/main >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: invalid ref format: ~a " err
+	test_grep "fatal: invalid ref format: ~a " err
 '
 
 test_expect_success 'update-ref --stdin -z fails update with bad ref name' '
 	printf "%s\0" "update ~a" refs/heads/main "" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: invalid ref format: ~a" err
+	test_grep "fatal: invalid ref format: ~a" err
 '
 
 test_expect_success 'update-ref --stdin -z fails delete with bad ref name' '
 	printf "%s\0" "delete ~a" refs/heads/main >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&
-	grep "fatal: invalid ref format: ~a" err
+	test_grep "fatal: invalid ref format: ~a" err
 '
 
 test_expect_success 'branch rejects HEAD as a branch name' '

@@ -68,7 +68,7 @@ test_expect_success 'object with hash mismatch' '
 		git update-ref refs/heads/bogus $cmt &&
 
 		test_must_fail git fsck 2>out &&
-		grep "$oldoid: hash-path mismatch, found at: .*$new" out
+		test_grep "$oldoid: hash-path mismatch, found at: .*$new" out
 	)
 '
 

@@ -172,7 +172,7 @@ test_expect_success 'commit with multiple signatures is okay' '
 	test_when_finished "git update-ref -d refs/heads/bogus" &&
 	git fsck 2>out &&
 	cat out &&
-	! grep "commit $new" out
+	test_grep ! "commit $new" out
 '
 
 test_expect_success 'email without @ is okay' '

@@ -183,7 +183,7 @@ test_expect_success 'email without @ is okay' '
 	git update-ref refs/heads/bogus "$new" &&
 	test_when_finished "git update-ref -d refs/heads/bogus" &&
 	git fsck 2>out &&
-	! grep "commit $new" out
+	test_grep ! "commit $new" out
 '
 
 test_expect_success 'email with embedded > is not okay' '

@@ -626,7 +626,7 @@ test_expect_success 'fsck notices excessively large tree entry name' '
 		cd large-name &&
 		test_commit a-long-name &&
 		git -c fsck.largePathname=warn:10 fsck 2>out &&
-		grep "warning.*large pathname" out
+		test_grep "warning.*large pathname" out
 	)
 '
 

@@ -849,7 +849,7 @@ test_expect_success 'fsck errors in packed objects' '
 	test_must_fail git fsck 2>out &&
 	test_grep "error in commit $one.* - bad name" out &&
 	test_grep "error in commit $two.* - bad name" out &&
-	! grep corrupt out
+	test_grep ! corrupt out
 '
 
 test_expect_success 'fsck handles multiple packfiles with big blobs' '

@@ -1027,7 +1027,7 @@ test_expect_success 'bogus head does not fallback to all heads' '
 	test_when_finished "git rm --cached foo" &&
 	remove_object $blob &&
 	test_must_fail git fsck $ZERO_OID >out 2>&1 &&
-	! grep $blob out
+	test_grep ! $blob out
 '
 
 # Corrupt the checksum on the index.

@@ -46,7 +46,7 @@ check () {
 			echo "$content"
 		} >input &&
 		test_must_fail git hash-object -t "$type" input 2>err &&
-		grep "$fsck" err
+		test_grep "$fsck" err
 	'
 }
 

@@ -125,7 +125,7 @@ ident_checks tag tagger
 test_expect_success 'truncated tree (short hash)' '
 	printf "100644 foo\0\1\1\1\1" >input &&
 	test_must_fail git hash-object -t tree input 2>err &&
-	grep badTree err
+	test_grep badTree err
 '
 
 test_expect_success 'truncated tree (missing nul)' '

@@ -135,7 +135,7 @@ test_expect_success 'truncated tree (missing nul)' '
 	# parser does not walk past the end of the buffer).
 	printf "100644 a long filename, or a hash with missing nul?" >input &&
 	test_must_fail git hash-object -t tree input 2>err &&
-	grep badTree err
+	test_grep badTree err
 '
 
 test_done

@@ -212,7 +212,7 @@ do
 			test_commit -C repo initial &&
 			git -C repo refs migrate --dry-run \
 				--ref-format=$to_format >output &&
-			grep "Finished dry-run migration of refs" output &&
+			test_grep "Finished dry-run migration of refs" output &&
 			test_path_is_dir repo/.git/ref_migration.* &&
 			echo $from_format >expect &&
 			git -C repo rev-parse --show-ref-format >actual &&

@@ -204,7 +204,7 @@ test_expect_success 'rev-parse --show-object-format in repo' '
 	git rev-parse --show-object-format=output >actual &&
 	test_cmp expect actual &&
 	test_must_fail git rev-parse --show-object-format=squeamish-ossifrage 2>err &&
-	grep "unknown mode for --show-object-format: squeamish-ossifrage" err
+	test_grep "unknown mode for --show-object-format: squeamish-ossifrage" err
 '
 
 

@@ -228,7 +228,7 @@ test_expect_success RUST 'rev-parse --show-object-format in repo with compat mod
 		git rev-parse --show-object-format=compat >actual &&
 		test_cmp expect actual &&
 		test_must_fail git rev-parse --show-object-format=squeamish-ossifrage 2>err &&
-		grep "unknown mode for --show-object-format: squeamish-ossifrage" err
+		test_grep "unknown mode for --show-object-format: squeamish-ossifrage" err
 	) &&
 	mkdir repo2 &&
 	(

@@ -254,7 +254,7 @@ test_expect_success 'rev-parse --show-ref-format with invalid storage' '
 		cd repo &&
 		git config extensions.refstorage broken &&
 		test_must_fail git rev-parse --show-ref-format 2>err &&
-		grep "error: invalid value for ${SQ}extensions.refstorage${SQ}: ${SQ}broken${SQ}" err
+		test_grep "error: invalid value for ${SQ}extensions.refstorage${SQ}: ${SQ}broken${SQ}" err
 	)
 '
 

@@ -331,7 +331,7 @@ test_expect_success 'ambiguous: --no matches both --noble and --no-noble' '
 	EOF
 	test_expect_code 129 env GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS=false \
 	git rev-parse --parseopt -- <spec 2>err --no &&
-	grep "error: ambiguous option: no (could be --noble or --no-noble)" err
+	test_grep "error: ambiguous option: no (could be --noble or --no-noble)" err
 '
 
 test_done

@@ -62,15 +62,15 @@ test_expect_success 'works with one good rev' '
 
 test_expect_success 'fails with any bad rev or many good revs' '
 	test_must_fail git rev-parse --verify 2>error &&
-	grep "single revision" error &&
+	test_grep "single revision" error &&
 	test_must_fail git rev-parse --verify foo 2>error &&
-	grep "single revision" error &&
+	test_grep "single revision" error &&
 	test_must_fail git rev-parse --verify HEAD bar 2>error &&
-	grep "single revision" error &&
+	test_grep "single revision" error &&
 	test_must_fail git rev-parse --verify baz HEAD 2>error &&
-	grep "single revision" error &&
+	test_grep "single revision" error &&
 	test_must_fail git rev-parse --verify $HASH2 HEAD 2>error &&
-	grep "single revision" error
+	test_grep "single revision" error
 '
 
 test_expect_success 'fails silently when using -q' '

@@ -604,7 +604,7 @@ test_expect_success '#20b/c: core.worktree and core.bare conflict' '
 		cd 20b/.git &&
 		test_must_fail git status >/dev/null
 	) 2>message &&
-	grep "core.bare and core.worktree" message
+	test_grep "core.bare and core.worktree" message
 '
 
 test_expect_success '#20d: core.worktree and core.bare OK when working tree not needed' '

@@ -721,8 +721,8 @@ test_expect_success '#22.2: core.worktree and core.bare conflict' '
 		export GIT_DIR &&
 		test_must_fail git status 2>result
 	) &&
-	grep "core.bare and core.worktree" 22/.git/result &&
-	grep "core.bare and core.worktree" 22/result
+	test_grep "core.bare and core.worktree" 22/.git/result &&
+	test_grep "core.bare and core.worktree" 22/result
 '
 
 # Case #23: GIT_DIR + GIT_WORK_TREE(+core.worktree) suppresses bareness.

@@ -767,7 +767,7 @@ test_expect_success '#28: core.worktree and core.bare conflict (gitfile case)' '
 		cd 28 &&
 		test_must_fail git status
 	) 2>message &&
-	grep "core.bare and core.worktree" message
+	test_grep "core.bare and core.worktree" message
 '
 
 # Case #29: GIT_WORK_TREE(+core.worktree) overrides core.bare (gitfile case).

@@ -791,7 +791,7 @@ test_expect_success '#30: core.worktree and core.bare conflict (gitfile version)
 		cd 30 &&
 		test_must_fail env GIT_DIR=.git git status 2>result
 	) &&
-	grep "core.bare and core.worktree" 30/result
+	test_grep "core.bare and core.worktree" 30/result
 '
 
 # Case #31: GIT_DIR + GIT_WORK_TREE(+core.worktree) suppresses

@@ -378,7 +378,7 @@ test_expect_success 'ambiguous 40-hex ref' '
 	VAL=$(git commit-tree $TREE </dev/null) &&
 	git update-ref refs/heads/$REF $VAL &&
 	test $(git rev-parse $REF 2>err) = $REF &&
-	grep "refname.*${REF}.*ambiguous" err
+	test_grep "refname.*${REF}.*ambiguous" err
 '
 
 test_expect_success 'ambiguous short sha1 ref' '

@@ -387,7 +387,7 @@ test_expect_success 'ambiguous short sha1 ref' '
 	VAL=$(git commit-tree $TREE </dev/null) &&
 	git update-ref refs/heads/$REF $VAL &&
 	test $(git rev-parse $REF 2>err) = $VAL &&
-	grep "refname.*${REF}.*ambiguous" err
+	test_grep "refname.*${REF}.*ambiguous" err
 '
 
 test_expect_success 'ambiguity errors are not repeated (raw)' '

@@ -32,7 +32,7 @@ test_expect_success 'rev-parse --local-env-vars' '
 	git rev-parse --local-env-vars >actual &&
 	# we do not want to depend on the complete list here,
 	# so just look for something plausible
-	grep ^GIT_DIR actual
+	test_grep ^GIT_DIR actual
 '
 
 test_expect_success 'rev-parse --resolve-git-dir' '

@@ -79,7 +79,7 @@ test_expect_success 'git hook usage' '
 	test_expect_code 129 git hook run --unknown 2>err &&
 	test_expect_code 129 git hook list &&
 	test_expect_code 129 git hook list -h &&
-	grep "unknown option" err
+	test_grep "unknown option" err
 '
 
 test_expect_success 'git hook list: unknown hook name is rejected' '

@@ -361,9 +361,9 @@ test_expect_success 'hook can be configured for multiple events' '
 
 	# 'ghi' should be included in both 'pre-commit' and 'test-hook'
 	git hook list pre-commit >actual &&
-	grep "ghi" actual &&
+	test_grep "ghi" actual &&
 	git hook list --allow-unknown-hook-name test-hook >actual &&
-	grep "ghi" actual
+	test_grep "ghi" actual
 '
 
 test_expect_success 'git hook list shows hooks from the hookdir' '

@@ -569,7 +569,7 @@ test_expect_success 'git hook run a hook with a bad shebang' '
 	# TODO: We should emit the same (or at least a more similar)
 	# error on MINGW (essentially Git for Windows) and all other
 	# platforms.. See the OS-specific code in start_command()
-	grep -E "^(error|fatal): cannot (exec|spawn) .*bad-hooks/test-hook" err
+	test_grep -E "^(error|fatal): cannot (exec|spawn) .*bad-hooks/test-hook" err
 '
 
 test_expect_success 'stdin to hooks' '

@@ -826,8 +826,8 @@ test_expect_success 'git hook run -j2 warns for hooks not marked parallel=true'
 	# neither hook has parallel=true
 
 	git hook run --allow-unknown-hook-name -j2 test-hook >out 2>err &&
-	grep "hook .hook-1. is not marked as parallel=true" err &&
-	grep "hook .hook-2. is not marked as parallel=true" err
+	test_grep "hook .hook-1. is not marked as parallel=true" err &&
+	test_grep "hook .hook-2. is not marked as parallel=true" err
 '
 
 test_expect_success 'hook.jobs=1 config runs hooks in series' '

@@ -1068,7 +1068,7 @@ test_expect_success 'hook.jobs=-1 resolves to online_cpus()' '
 	cpus=$(test-tool online-cpus) &&
 	GIT_TRACE2_EVENT="$(pwd)/trace.txt" \
 		git hook run --allow-unknown-hook-name test-hook >out 2>err &&
-	grep "\"region_enter\".*\"hook\".*\"test-hook\".*\"max:$cpus\"" trace.txt
+	test_grep "\"region_enter\".*\"hook\".*\"test-hook\".*\"max:$cpus\"" trace.txt
 '
 
 test_expect_success 'hook.<event>.jobs=-1 resolves to online_cpus()' '

@@ -1081,7 +1081,7 @@ test_expect_success 'hook.<event>.jobs=-1 resolves to online_cpus()' '
 	cpus=$(test-tool online-cpus) &&
 	GIT_TRACE2_EVENT="$(pwd)/trace.txt" \
 		git hook run --allow-unknown-hook-name test-hook >out 2>err &&
-	grep "\"region_enter\".*\"hook\".*\"test-hook\".*\"max:$cpus\"" trace.txt
+	test_grep "\"region_enter\".*\"hook\".*\"test-hook\".*\"max:$cpus\"" trace.txt
 '
 
 test_expect_success 'git hook run -j-1 resolves to online_cpus()' '

@@ -1092,7 +1092,7 @@ test_expect_success 'git hook run -j-1 resolves to online_cpus()' '
 	cpus=$(test-tool online-cpus) &&
 	GIT_TRACE2_EVENT="$(pwd)/trace.txt" \
 		git hook run --allow-unknown-hook-name -j-1 test-hook >out 2>err &&
-	grep "\"region_enter\".*\"hook\".*\"test-hook\".*\"max:$cpus\"" trace.txt
+	test_grep "\"region_enter\".*\"hook\".*\"test-hook\".*\"max:$cpus\"" trace.txt
 '
 
 test_expect_success 'hook.jobs rejects values less than -1' '

@@ -132,8 +132,8 @@ test_expect_success 'overriding --stage=all resets implied --temp' '
 test_expect_success '--stage=all --no-temp is rejected' '
 	rm -f path* .merge_* actual &&
 	test_must_fail git checkout-index --stage=all --no-temp -- path1 2>err &&
-	grep -v "already exists" err &&
-	grep "options .--stage=all. and .--no-temp. cannot be used together" err
+	test_grep -v "already exists" err &&
+	test_grep "options .--stage=all. and .--no-temp. cannot be used together" err
 '
 
 test_expect_success 'checkout some stages/one file to temporary files' '

@@ -19,7 +19,7 @@ test_expect_success 'checkout ambiguous ref succeeds' '
 '
 
 test_expect_success 'checkout produces ambiguity warning' '
-	grep "warning.*ambiguous" stderr
+	test_grep "warning.*ambiguous" stderr
 '
 
 test_expect_success 'checkout chooses branch over tag' '

@@ -41,7 +41,7 @@ test_expect_success 'checkout vague ref succeeds' '
 '
 
 test_expect_success VAGUENESS_SUCCESS 'checkout produces ambiguity warning' '
-	grep "warning.*ambiguous" stderr
+	test_grep "warning.*ambiguous" stderr
 '
 
 test_expect_success VAGUENESS_SUCCESS 'checkout chooses branch over tag' '

@@ -311,7 +311,7 @@ test_expect_success 'loosely defined local base branch is reported correctly' '
 	git checkout loose >actual.raw 2>&1 &&
 	sed -e "s/loose/BRANCHNAME/g" <actual.raw >actual &&
 	status_uno_is_clean &&
-	grep BRANCHNAME actual &&
+	test_grep BRANCHNAME actual &&
 
 	test_cmp expect actual
 '

@@ -324,7 +324,7 @@ test_expect_success 'reject when arg could be part of dwim branch' '
 	echo bar >dwim-arg &&
 	test_must_fail git checkout dwim-arg &&
 	test_must_fail git rev-parse refs/heads/dwim-arg -- &&
-	grep bar dwim-arg
+	test_grep bar dwim-arg
 '
 
 test_expect_success 'disambiguate dwim branch and checkout path (1)' '

@@ -334,7 +334,7 @@ test_expect_success 'disambiguate dwim branch and checkout path (1)' '
 	echo bar >dwim-arg1 &&
 	git checkout -- dwim-arg1 &&
 	test_must_fail git rev-parse refs/heads/dwim-arg1 -- &&
-	grep foo dwim-arg1
+	test_grep foo dwim-arg1
 '
 
 test_expect_success 'disambiguate dwim branch and checkout path (2)' '

@@ -344,7 +344,7 @@ test_expect_success 'disambiguate dwim branch and checkout path (2)' '
 	echo bar >dwim-arg2 &&
 	git checkout dwim-arg2 -- &&
 	git rev-parse refs/heads/dwim-arg2 -- &&
-	grep bar dwim-arg2
+	test_grep bar dwim-arg2
 '
 
 test_done

@@ -122,7 +122,7 @@ test_expect_success 'add records checkout -m undoes' '
 	check_resolve_undo removed &&
 	echo the index and the work tree is unmerged again &&
 	git diff >actual &&
-	grep "^++<<<<<<<" actual
+	test_grep "^++<<<<<<<" actual
 '
 
 test_expect_success 'unmerge with plumbing' '

@@ -173,7 +173,7 @@ test_expect_success 'rerere and rerere forget' '
 	test -f .git/rr-cache/$rerere_id/postimage &&
 	git checkout -m fi/le &&
 	echo resurrect the conflict &&
-	grep "^=======" fi/le &&
+	test_grep "^=======" fi/le &&
 	echo reresolve the conflict &&
 	git rerere &&
 	test "z$(cat fi/le)" = zdifferent &&

@@ -199,7 +199,7 @@ test_expect_success 'rerere and rerere forget (subdirectory)' '
 	test -f .git/rr-cache/$rerere_id/postimage &&
 	(cd fi && git checkout -m le) &&
 	echo resurrect the conflict &&
-	grep "^=======" fi/le &&
+	test_grep "^=======" fi/le &&
 	echo reresolve the conflict &&
 	(cd fi && git rerere) &&
 	test "z$(cat fi/le)" = zdifferent &&

@@ -34,13 +34,13 @@ test_expect_success 'switch and detach' '
 
 test_expect_success 'suggestion to detach' '
 	test_must_fail git switch main^{commit} 2>stderr &&
-	grep "try again with the --detach option" stderr
+	test_grep "try again with the --detach option" stderr
 '
 
 test_expect_success 'suggestion to detach is suppressed with advice.suggestDetachingHead=false' '
 	test_config advice.suggestDetachingHead false &&
 	test_must_fail git switch main^{commit} 2>stderr &&
-	! grep "try again with the --detach option" stderr
+	test_grep ! "try again with the --detach option" stderr
 '
 
 test_expect_success 'switch and detach current branch' '

@@ -76,7 +76,7 @@ test_expect_success 'new orphan branch from empty' '
 	git switch --orphan new-orphan &&
 	test_commit orphan &&
 	git cat-file commit refs/heads/new-orphan >commit &&
-	! grep ^parent commit &&
+	test_grep ! ^parent commit &&
 	git ls-files >tracked-files &&
 	echo orphan.t >expected &&
 	test_cmp expected tracked-files

@@ -216,7 +216,7 @@ test_expect_success 'restore with merge options are incompatible with certain op
 		"--staged --worktree --conflict=zdiff3"
 	do
 		test_must_fail git restore $opts . 2>err &&
-		grep "cannot be used" err || return
+		test_grep "cannot be used" err || return
 	done
 '
 

@@ -200,13 +200,13 @@ test_expect_success 'parallel checkout respects --[no]-force' '
 		# We expect 0 workers because there is nothing to be done
 		test_checkout_workers 0 git checkout HEAD &&
 		test_path_is_file D &&
-		grep changed D &&
-		grep changed F.t &&
+		test_grep changed D &&
+		test_grep changed F.t &&
 
 		test_checkout_workers 2 git checkout --force HEAD &&
 		test_path_is_dir D &&
-		grep D/F D/F.t &&
-		grep F F.t
+		test_grep D/F D/F.t &&
+		test_grep F F.t
 	)
 '
 

@@ -224,8 +224,8 @@ test_expect_success SYMLINKS 'parallel checkout checks for symlinks in leading d
 
 		test_checkout_workers 2 git checkout --force HEAD &&
 		! test -h D &&
-		grep D/A D/A.t &&
-		grep D/B D/B.t
+		test_grep D/A D/A.t &&
+		test_grep D/B D/B.t
 	)
 '
 

@@ -268,7 +268,7 @@ test_expect_success '"git checkout ." report should not include failed entries'
 		#  - missing-delay.a: the delay filter will drop this path
 		#  - parallel-*.a: the blob will be missing
 		#
-		grep "Updated 3 paths from the index" err &&
+		test_grep "Updated 3 paths from the index" err &&
 		test_stdout_line_count = 3 ls *.b &&
 		! ls *.a
 	)

@@ -78,8 +78,8 @@ test_expect_success CASE_INSENSITIVE_FS 'worker detects dirname collision' '
 
 	# Check that it used the right number of workers and detected the collisions
 	test_workers_in_event_trace 2 trace &&
-	grep "category.:.pcheckout.,.key.:.collision/dirname.,.value.:.A/B.}" trace &&
-	grep "category.:.pcheckout.,.key.:.collision/dirname.,.value.:.A/C.}" trace
+	test_grep "category.:.pcheckout.,.key.:.collision/dirname.,.value.:.A/B.}" trace &&
+	test_grep "category.:.pcheckout.,.key.:.collision/dirname.,.value.:.A/C.}" trace
 '
 
 test_expect_success SYMLINKS,CASE_INSENSITIVE_FS 'do not follow symlinks colliding with leading dir' '

@@ -115,11 +115,11 @@ test_expect_success CASE_INSENSITIVE_FS 'collision report on clone (w/ racy file
 	set_checkout_config 2 0 &&
 	test_checkout_workers 2 git clone . clone-repo 2>stderr &&
 
-	grep FILE_X stderr &&
-	grep FILE_x stderr &&
-	grep file_X stderr &&
-	grep file_x stderr &&
-	grep "the following paths have collided" stderr
+	test_grep FILE_X stderr &&
+	test_grep FILE_x stderr &&
+	test_grep file_X stderr &&
+	test_grep file_x stderr &&
+	test_grep "the following paths have collided" stderr
 '
 
 # This test ensures that the collision report code is correctly looking for

@@ -148,11 +148,11 @@ test_expect_success CASE_INSENSITIVE_FS,!MINGW,!CYGWIN \
 	test_checkout_workers 2 \
 		git -c core.ignoreCase=false clone . clone-repo 2>stderr &&
 
-	grep FILE_X stderr &&
-	grep FILE_x stderr &&
-	grep file_X stderr &&
-	grep file_x stderr &&
-	grep "the following paths have collided" stderr &&
+	test_grep FILE_X stderr &&
+	test_grep FILE_x stderr &&
+	test_grep file_X stderr &&
+	test_grep file_x stderr &&
+	test_grep "the following paths have collided" stderr &&
 
 	# Check that only "file_x" was filtered
 	echo file_x >expected.log &&

@@ -28,8 +28,8 @@ test_expect_success 'parallel-checkout with ident' '
 		rm A B &&
 		test_checkout_workers 2 git reset --hard &&
 		hexsz=$(test_oid hexsz) &&
-		grep -E "\\\$Id: [0-9a-f]{$hexsz} \\\$" A &&
-		grep "\\\$Id\\\$" B
+		test_grep -E "\\\$Id: [0-9a-f]{$hexsz} \\\$" A &&
+		test_grep "\\\$Id\\\$" B
 	)
 '
 

@@ -175,15 +175,15 @@ test_expect_success 'parallel-checkout and delayed checkout' '
 	verify_checkout delayed &&
 
 	# Check that the *.d files got to the delay queue and were filtered
-	grep "smudge W.d .* \[DELAYED\]" delayed.log &&
-	grep "smudge X.d .* \[DELAYED\]" delayed.log &&
+	test_grep "smudge W.d .* \[DELAYED\]" delayed.log &&
+	test_grep "smudge X.d .* \[DELAYED\]" delayed.log &&
 	test_cmp delayed/W.d original &&
 	test_cmp delayed/X.d original &&
 
 	# Check that the parallel-eligible entries went to the right queue and
 	# were not filtered
-	! grep "smudge Y .* \[DELAYED\]" delayed.log &&
-	! grep "smudge Z .* \[DELAYED\]" delayed.log &&
+	test_grep ! "smudge Y .* \[DELAYED\]" delayed.log &&
+	test_grep ! "smudge Z .* \[DELAYED\]" delayed.log &&
 	test_cmp delayed/Y original &&
 	test_cmp delayed/Z original
 '

@@ -63,9 +63,9 @@ test_expect_success '--unmerged --refresh' '
 	git update-index --unmerged --refresh &&
 	echo 2 >two &&
 	test_must_fail git update-index --unmerged --refresh >actual &&
-	grep two actual &&
-	! grep one actual &&
-	! grep three actual
+	test_grep two actual &&
+	test_grep ! one actual &&
+	test_grep ! three actual
 '
 
 test_expect_success '--ignore-submodules --refresh (1)' '

@@ -241,7 +241,7 @@ test_expect_success 'add -u avoids rename pairing on unmerged paths' '
 test_expect_success '"add -u non-existent" should fail' '
 	test_must_fail git add -u non-existent &&
 	git ls-files >actual &&
-	! grep "non-existent" actual
+	test_grep ! "non-existent" actual
 '
 
 test_expect_success '"commit -a" implies "add -u" if index becomes empty' '

@@ -57,7 +57,7 @@ test_expect_success 'intent to add does not clobber existing paths' '
 	git add -N file elif &&
 	empty=$(git hash-object --stdin </dev/null) &&
 	git ls-files -s >actual &&
-	! grep "$empty" actual
+	test_grep ! "$empty" actual
 '
 
 test_expect_success 'i-t-a entry is simply ignored' '

@@ -124,7 +124,7 @@ test_expect_success 'cache-tree does not ignore dir that has i-t-a entries' '
 		git add -N 2/1 &&
 		git commit -m committed &&
 		git ls-tree -r HEAD >actual &&
-		grep 2/2 actual
+		test_grep 2/2 actual
 	)
 '
 

@@ -312,7 +312,7 @@ test_expect_success 'apply --intent-to-add' '
 	echo new >new-ita &&
 	git add -N new-ita &&
 	git diff >expected &&
-	grep "new file" expected &&
+	test_grep "new file" expected &&
 	git reset --hard &&
 	git apply --intent-to-add expected &&
 	git diff >actual &&

@@ -122,7 +122,7 @@ test_expect_success 'die the same branch is already checked out' '
 	(
 		cd here &&
 		test_must_fail git checkout newmain 2>actual &&
-		grep "already used by worktree at" actual
+		test_grep "already used by worktree at" actual
 	)
 '
 

@@ -139,7 +139,7 @@ test_expect_success 'refuse to reset a branch in use elsewhere' '
 		git rev-parse --verify refs/heads/newmain >new.branch &&
 		git rev-parse --verify HEAD >new.head &&
 
-		grep "already used by worktree at" error &&
+		test_grep "already used by worktree at" error &&
 		test_cmp old.branch new.branch &&
 		test_cmp old.head new.head &&
 

@@ -328,7 +328,7 @@ test_wt_add_excl () {
 	local opts="$*" &&
 	test_expect_success "'worktree add' with '$opts' has mutually exclusive options" '
 		test_must_fail git worktree add $opts 2>actual &&
-		grep -E "fatal:( options)? .* cannot be used together" actual
+		test_grep -E "fatal:( options)? .* cannot be used together" actual
 	'
 }
 

@@ -436,13 +436,13 @@ test_wt_add_orphan_hint () {
 		(cd repo && test_commit commit) &&
 		git -C repo switch --orphan noref &&
 		test_must_fail git -C repo worktree add $opts foobar/ 2>actual &&
-		! grep "error: unknown switch" actual &&
-		grep "hint: If you meant to create a worktree containing a new unborn branch" actual &&
+		test_grep ! "error: unknown switch" actual &&
+		test_grep "hint: If you meant to create a worktree containing a new unborn branch" actual &&
 		if [ $use_branch -eq 1 ]
 		then
-			grep -E "^hint: +git worktree add --orphan -b [^ ]+ [^ ]+$" actual
+			test_grep -E "^hint: +git worktree add --orphan -b [^ ]+ [^ ]+$" actual
 		else
-			grep -E "^hint: +git worktree add --orphan [^ ]+$" actual
+			test_grep -E "^hint: +git worktree add --orphan [^ ]+$" actual
 		fi
 
 	'

@@ -457,8 +457,8 @@ test_expect_success "'worktree add' doesn't show orphan hint in bad/orphan HEAD
 	git init repo &&
 	(cd repo && test_commit commit) &&
 	test_must_fail git -C repo worktree add --quiet foobar_branch foobar/ 2>actual &&
-	! grep "error: unknown switch" actual &&
-	! grep "hint: If you meant to create a worktree containing a new unborn branch" actual
+	test_grep ! "error: unknown switch" actual &&
+	test_grep ! "hint: If you meant to create a worktree containing a new unborn branch" actual
 '
 
 test_expect_success 'local clone from linked checkout' '

@@ -469,7 +469,7 @@ test_expect_success 'local clone from linked checkout' '
 test_expect_success 'local clone --shared from linked checkout' '
 	git -C bare worktree add --detach ../baretree &&
 	git clone --local --shared baretree bare-clone &&
-	grep /bare/ bare-clone/.git/objects/info/alternates
+	test_grep /bare/ bare-clone/.git/objects/info/alternates
 '
 
 test_expect_success '"add" worktree with --no-checkout' '

@@ -491,7 +491,7 @@ test_expect_success 'put a worktree under rebase' '
 		set_fake_editor &&
 		FAKE_LINES="edit 1" git rebase -i HEAD^ &&
 		git worktree list >actual &&
-		grep "under-rebase.*detached HEAD" actual
+		test_grep "under-rebase.*detached HEAD" actual
 	)
 '
 

@@ -533,7 +533,7 @@ test_expect_success 'checkout a branch under bisect' '
 		git bisect bad &&
 		git bisect good HEAD~2 &&
 		git worktree list >actual &&
-		grep "under-bisect.*detached HEAD" actual &&
+		test_grep "under-bisect.*detached HEAD" actual &&
 		test_must_fail git worktree add new-bisect under-bisect &&
 		test_path_is_missing new-bisect
 	)

@@ -101,8 +101,8 @@ test_expect_success '"list" all worktrees with locked annotation' '
 	git worktree lock locked &&
 	test_when_finished "git worktree unlock locked" &&
 	git worktree list >out &&
-	grep "/locked  *[0-9a-f].* locked$" out &&
-	! grep "/unlocked  *[0-9a-f].* locked$" out
+	test_grep "/locked  *[0-9a-f].* locked$" out &&
+	test_grep ! "/unlocked  *[0-9a-f].* locked$" out
 '
 
 test_expect_success '"list" all worktrees --porcelain with locked' '

@@ -143,8 +143,8 @@ test_expect_success '"list" all worktrees with prunable annotation' '
 	git worktree add --detach unprunable &&
 	rm -rf prunable &&
 	git worktree list >out &&
-	grep "/prunable  *[0-9a-f].* prunable$" out &&
-	! grep "/unprunable  *[0-9a-f].* prunable$" out
+	test_grep "/prunable  *[0-9a-f].* prunable$" out &&
+	test_grep ! "/unprunable  *[0-9a-f].* prunable$" out
 '
 
 test_expect_success '"list" all worktrees --porcelain with prunable' '

@@ -162,8 +162,8 @@ test_expect_success '"list" all worktrees with prunable consistent with "prune"'
 	git worktree add --detach unprunable &&
 	rm -rf prunable &&
 	git worktree list >out &&
-	grep "/prunable  *[0-9a-f].* prunable$" out &&
-	! grep "/unprunable  *[0-9a-f].* unprunable$" out &&
+	test_grep "/prunable  *[0-9a-f].* prunable$" out &&
+	test_grep ! "/unprunable  *[0-9a-f].* unprunable$" out &&
 	git worktree prune --verbose 2>out &&
 	test_grep "^Removing worktrees/prunable" out &&
 	test_grep ! "^Removing worktrees/unprunable" out

@@ -184,7 +184,7 @@ test_expect_success '"list" all worktrees --verbose with locked' '
 	echo "$(git -C locked2 rev-parse --show-toplevel) $(git rev-parse --short HEAD) (detached HEAD)" >expect &&
 	printf "\tlocked: with reason\n" >>expect &&
 	git worktree list --verbose >out &&
-	grep "/locked1  *[0-9a-f].* locked$" out &&
+	test_grep "/locked1  *[0-9a-f].* locked$" out &&
 	sed -n "s/  */ /g;/\/locked2  *[0-9a-f].*$/,/locked: .*$/p" <out >actual &&
 	test_cmp actual expect
 '

@@ -266,7 +266,7 @@ test_expect_success 'broken main worktree still at the top' '
 		test_cmp ../expected actual &&
 		git worktree list >out &&
 		head -n 1 out >actual.2 &&
-		grep -F "(error)" actual.2
+		test_grep -F "(error)" actual.2
 	)
 '
 

@@ -75,8 +75,8 @@ test_expect_success 'move worktree' '
 	git worktree move source destination &&
 	test_path_is_missing source &&
 	git worktree list --porcelain >out &&
-	grep "^worktree.*/destination$" out &&
-	! grep "^worktree.*/source$" out &&
+	test_grep "^worktree.*/destination$" out &&
+	test_grep ! "^worktree.*/source$" out &&
 	git -C destination log --format=%s >actual2 &&
 	echo init >expected2 &&
 	test_cmp expected2 actual2

@@ -92,7 +92,7 @@ test_expect_success 'move worktree to another dir' '
 	test_when_finished "git worktree move some-dir/destination destination" &&
 	test_path_is_missing destination &&
 	git worktree list --porcelain >out &&
-	grep "^worktree.*/some-dir/destination$" out &&
+	test_grep "^worktree.*/some-dir/destination$" out &&
 	git -C some-dir/destination log --format=%s >actual2 &&
 	echo init >expected2 &&
 	test_cmp expected2 actual2

@@ -36,7 +36,7 @@ test_expect_success 'add superproject worktree' '
 
 test_expect_failure 'submodule is checked out just after worktree add' '
 	git -C worktree diff --submodule main"^!" >out &&
-	grep "file1 updated" out
+	test_grep "file1 updated" out
 '
 
 test_expect_success 'add superproject worktree and initialize submodules' '

@@ -46,7 +46,7 @@ test_expect_success 'add superproject worktree and initialize submodules' '
 
 test_expect_success 'submodule is checked out just after submodule update in linked worktree' '
 	git -C worktree-submodule-update diff --submodule main"^!" >out &&
-	grep "file1 updated" out
+	test_grep "file1 updated" out
 '
 
 test_expect_success 'add superproject worktree and manually add submodule worktree' '

@@ -56,7 +56,7 @@ test_expect_success 'add superproject worktree and manually add submodule worktr
 
 test_expect_success 'submodule is checked out after manually adding submodule worktree' '
 	git -C linked_submodule diff --submodule main"^!" >out &&
-	grep "file1 updated" out
+	test_grep "file1 updated" out
 '
 
 test_expect_success 'checkout --recurse-submodules uses $GIT_DIR for submodules in a linked worktree' '

@@ -41,10 +41,10 @@ test_expect_success 'refuse to overwrite: checked out in worktree' '
 	for i in 1 2 3 4
 	do
 		test_must_fail git branch -f wt-$i HEAD 2>err &&
-		grep "cannot force update the branch" err &&
+		test_grep "cannot force update the branch" err &&
 
 		test_must_fail git branch -D wt-$i 2>err &&
-		grep "cannot delete branch" err || return 1
+		test_grep "cannot delete branch" err || return 1
 	done
 '
 

@@ -57,7 +57,7 @@ test_expect_success 'refuse to overwrite: worktree in bisect' '
 	git -C wt-4 bisect good wt-1 &&
 
 	test_must_fail git branch -f wt-4 HEAD 2>err &&
-	grep "cannot force update the branch '\''wt-4'\'' used by worktree at.*wt-4" err
+	test_grep "cannot force update the branch '\''wt-4'\'' used by worktree at.*wt-4" err
 '
 
 test_expect_success 'refuse to overwrite: worktree in rebase (apply)' '

@@ -67,7 +67,7 @@ test_expect_success 'refuse to overwrite: worktree in rebase (apply)' '
 	test_must_fail git -C wt-2 rebase --apply conflict-2 &&
 
 	test_must_fail git branch -f wt-2 HEAD 2>err &&
-	grep "cannot force update the branch '\''wt-2'\'' used by worktree at.*wt-2" err
+	test_grep "cannot force update the branch '\''wt-2'\'' used by worktree at.*wt-2" err
 '
 
 test_expect_success 'refuse to overwrite: worktree in rebase (merge)' '

@@ -77,7 +77,7 @@ test_expect_success 'refuse to overwrite: worktree in rebase (merge)' '
 	test_must_fail git -C wt-2 rebase conflict-2 &&
 
 	test_must_fail git branch -f wt-2 HEAD 2>err &&
-	grep "cannot force update the branch '\''wt-2'\'' used by worktree at.*wt-2" err
+	test_grep "cannot force update the branch '\''wt-2'\'' used by worktree at.*wt-2" err
 '
 
 test_expect_success 'refuse to overwrite: worktree in rebase with --update-refs' '

@@ -89,19 +89,19 @@ test_expect_success 'refuse to overwrite: worktree in rebase with --update-refs'
 	for i in 3 4
 	do
 		test_must_fail git branch -f can-be-updated HEAD 2>err &&
-		grep "cannot force update the branch '\''can-be-updated'\'' used by worktree at.*wt-3" err ||
+		test_grep "cannot force update the branch '\''can-be-updated'\'' used by worktree at.*wt-3" err ||
 			return 1
 	done
 '
 
 test_expect_success 'refuse to fetch over ref: checked out' '
 	test_must_fail git fetch server +refs/heads/wt-3:refs/heads/wt-3 2>err &&
-	grep "refusing to fetch into branch '\''refs/heads/wt-3'\''" err &&
+	test_grep "refusing to fetch into branch '\''refs/heads/wt-3'\''" err &&
 
 	# General fetch into refs/heads/ will fail on first ref,
 	# so use a generic error message check.
 	test_must_fail git fetch server +refs/heads/*:refs/heads/* 2>err &&
-	grep "refusing to fetch into branch" err
+	test_grep "refusing to fetch into branch" err
 '
 
 test_expect_success 'refuse to fetch over ref: worktree in bisect' '

@@ -113,7 +113,7 @@ test_expect_success 'refuse to fetch over ref: worktree in bisect' '
 	git -C wt-4 bisect good wt-1 &&
 
 	test_must_fail git fetch server +refs/heads/wt-4:refs/heads/wt-4 2>err &&
-	grep "refusing to fetch into branch" err
+	test_grep "refusing to fetch into branch" err
 '
 
 test_expect_success 'refuse to fetch over ref: worktree in rebase' '

@@ -123,7 +123,7 @@ test_expect_success 'refuse to fetch over ref: worktree in rebase' '
 	test_must_fail git -C wt-3 rebase conflict-3 &&
 
 	test_must_fail git fetch server +refs/heads/wt-3:refs/heads/wt-3 2>err &&
-	grep "refusing to fetch into branch" err
+	test_grep "refusing to fetch into branch" err
 '
 
 test_expect_success 'refuse to overwrite when in error states' '

@@ -149,7 +149,7 @@ test_expect_success 'refuse to overwrite when in error states' '
 	for i in 1 2
 	do
 		test_must_fail git branch -f fake-$i HEAD 2>err &&
-		grep "cannot force update the branch '\''fake-$i'\'' used by worktree at" err ||
+		test_grep "cannot force update the branch '\''fake-$i'\'' used by worktree at" err ||
 			return 1
 	done
 '

@@ -161,13 +161,13 @@ test_expect_success 'refuse to overwrite during rebase with --update-refs' '
 	(
 		set_cat_todo_editor &&
 		test_must_fail git rebase -i --update-refs HEAD~3 >todo &&
-		! grep "update-refs" todo
+		test_grep ! "update-refs" todo
 	) &&
 	git branch -f allow-update HEAD~2 &&
 	(
 		set_cat_todo_editor &&
 		test_must_fail git rebase -i --update-refs HEAD~3 >todo &&
-		grep "update-ref refs/heads/allow-update" todo
+		test_grep "update-ref refs/heads/allow-update" todo
 	)
 '
 

@@ -51,7 +51,7 @@ test_expect_success 'reset --merge will preserve untracked files/dirs' '
 
 		test_must_fail git reset --merge work 2>error &&
 		test_cmp expect foo.t/file &&
-		grep "Updating .foo.t. would lose untracked files" error
+		test_grep "Updating .foo.t. would lose untracked files" error
 	)
 '
 

@@ -66,7 +66,7 @@ test_expect_success 'reset --keep will preserve untracked files/dirs' '
 
 		test_must_fail git reset --merge work 2>error &&
 		test_cmp expect foo.t/file &&
-		grep "Updating.*foo.t.*would lose untracked files" error
+		test_grep "Updating.*foo.t.*would lose untracked files" error
 	)
 '
 

@@ -214,7 +214,7 @@ test_expect_success 'git am --abort and untracked dir vs. unmerged file' '
 
 		test_must_fail git am --abort 2>errors &&
 		test_path_is_dir filler &&
-		grep "Updating .filler. would lose untracked files in it" errors
+		test_grep "Updating .filler. would lose untracked files in it" errors
 	)
 '
 

@@ -237,7 +237,7 @@ test_expect_success 'git am --skip and untracked dir vs deleted file' '
 		# Change our mind about resolutions, just skip this patch
 		test_must_fail git am --skip 2>errors &&
 		test_path_is_dir newfile &&
-		grep "Updating .newfile. would lose untracked files in it" errors
+		test_grep "Updating .newfile. would lose untracked files in it" errors
 	)
 '
 

@@ -114,7 +114,7 @@ test_expect_success 'merge fails if cwd needs to be removed; recursive friendly'
 	) &&
 
 	test_path_is_dir dirORfile &&
-	grep "Refusing to remove the current working directory" error
+	test_grep "Refusing to remove the current working directory" error
 '
 
 test_expect_success 'merge fails if cwd needs to be removed' '

@@ -179,7 +179,7 @@ test_incidental_untracked_dir_removal () {
 test_expect_success 'clean does not remove cwd incidentally' '
 	test_incidental_untracked_dir_removal \
 		git -C .. clean -fd -e warnings . >warnings &&
-	grep "Refusing to remove current working directory" warnings
+	test_grep "Refusing to remove current working directory" warnings
 '
 
 test_expect_success 'stash does not remove cwd incidentally' '

@@ -161,21 +161,21 @@ test_expect_success 'trailing slash in exclude forces directory match (1)' '
 
 	>two &&
 	git ls-files --others --exclude=two/ >output &&
-	grep "^two" output
+	test_grep "^two" output
 
 '
 
 test_expect_success 'trailing slash in exclude forces directory match (2)' '
 
 	git ls-files --others --exclude=one/a.1/ >output &&
-	grep "^one/a.1" output
+	test_grep "^one/a.1" output
 
 '
 
 test_expect_success 'negated exclude matches can override previous ones' '
 
 	git ls-files --others --exclude="a.*" --exclude="!a.1" >output &&
-	grep "^a.1" output
+	test_grep "^a.1" output
 '
 
 test_expect_success 'excluded directory overrides content patterns' '

@@ -302,7 +302,7 @@ test_expect_success '--recurse-submodules does not support --error-unmatch' '
 test_expect_success '--recurse-submodules parses submodule repo config' '
 	test_config -C submodule index.sparse "invalid non-boolean value" &&
 	test_must_fail git ls-files --recurse-submodules 2>err &&
-	grep "bad boolean config value" err
+	test_grep "bad boolean config value" err
 '
 
 test_expect_success '--recurse-submodules parses submodule worktree config' '

@@ -310,7 +310,7 @@ test_expect_success '--recurse-submodules parses submodule worktree config' '
 	test_config -C submodule --worktree index.sparse "invalid non-boolean value" &&
 
 	test_must_fail git ls-files --recurse-submodules 2>err &&
-	grep "bad boolean config value" err
+	test_grep "bad boolean config value" err
 '
 
 test_expect_success '--recurse-submodules submodules ignore super project worktreeConfig extension' '

@@ -329,7 +329,7 @@ test_expect_success '--recurse-submodules submodules ignore super project worktr
 	# With extensions.worktreeConfig disabled in the submodule, the invalid
 	# worktree config is not picked up.
 	git ls-files --recurse-submodules 2>err &&
-	! grep "bad boolean config value" err
+	test_grep ! "bad boolean config value" err
 '
 
 test_incompatible_with_recurse_submodules () {

@@ -204,7 +204,7 @@ test_expect_success 'git branch -M baz bam should succeed when baz is checked ou
 
 test_expect_success 'git branch -M baz bam should add entries to HEAD reflog' '
 	git reflog show HEAD >actual &&
-	grep "HEAD@{0}: Branch: renamed refs/heads/baz to refs/heads/bam" actual
+	test_grep "HEAD@{0}: Branch: renamed refs/heads/baz to refs/heads/bam" actual
 '
 
 test_expect_success 'git branch -M should leave orphaned HEAD alone' '

@@ -339,7 +339,7 @@ test_expect_success 'git branch -d on orphan HEAD (unmerged)' '
 	test_when_finished "git branch -D to-delete" &&
 	git branch to-delete main &&
 	test_must_fail git branch -d to-delete 2>err &&
-	grep "not fully merged" err
+	test_grep "not fully merged" err
 '
 
 test_expect_success 'git branch -d on orphan HEAD (unmerged, graph)' '

@@ -350,7 +350,7 @@ test_expect_success 'git branch -d on orphan HEAD (unmerged, graph)' '
 	test_when_finished "rm -rf .git/objects/commit-graph*" &&
 	git commit-graph write --reachable &&
 	test_must_fail git branch -d to-delete 2>err &&
-	grep "not fully merged" err
+	test_grep "not fully merged" err
 '
 
 test_expect_success 'git branch -v -d t should work' '

@@ -712,7 +712,7 @@ test_expect_success 'git branch -C c1 c2 should succeed when c1 is checked out'
 test_expect_success 'git branch -C c1 c2 should never touch HEAD' '
 	msg="Branch: copied refs/heads/c1 to refs/heads/c2" &&
 	git reflog HEAD >actual &&
-	! grep "$msg$" actual
+	test_grep ! "$msg$" actual
 '
 
 test_expect_success 'git branch -C main should work when main is checked out' '

@@ -930,7 +930,7 @@ test_expect_success 'deleting currently checked out branch fails' '
 	git worktree add -b my7 my7 &&
 	test_must_fail git -C my7 branch -d my7 &&
 	test_must_fail git branch -d my7 2>actual &&
-	grep "^error: cannot delete branch .my7. used by worktree at " actual &&
+	test_grep "^error: cannot delete branch .my7. used by worktree at " actual &&
 	rm -r my7 &&
 	git worktree prune
 '

@@ -941,7 +941,7 @@ test_expect_success 'deleting in-use branch fails' '
 	git -C my7 bisect start HEAD HEAD~2 &&
 	test_must_fail git -C my7 branch -d my7 &&
 	test_must_fail git branch -d my7 2>actual &&
-	grep "^error: cannot delete branch .my7. used by worktree at " actual &&
+	test_grep "^error: cannot delete branch .my7. used by worktree at " actual &&
 	rm -r my7 &&
 	git worktree prune
 '

@@ -123,13 +123,13 @@ test_expect_success 'show-branch --sparse' '
 	git commit --allow-empty -m "another" &&
 
 	git show-branch --sparse >out &&
-	grep "merge 1 and 10 to make A" out &&
+	test_grep "merge 1 and 10 to make A" out &&
 
 	git show-branch >out &&
-	! grep "merge 1 and 10 to make A" out &&
+	test_grep ! "merge 1 and 10 to make A" out &&
 
 	git show-branch --no-sparse >out &&
-	! grep "merge 1 and 10 to make A" out
+	test_grep ! "merge 1 and 10 to make A" out
 '
 
 test_expect_success 'setup show branch --list' '

@@ -189,7 +189,7 @@ while read combo
 do
 	test_expect_success "show-branch $combo (should fail)" '
 		test_must_fail git show-branch $combo 2>error &&
-		grep -e "cannot be used together" -e "usage:" error
+		test_grep -e "cannot be used together" -e "usage:" error
 	'
 done <<\EOF
 --all --reflog

@@ -203,7 +203,7 @@ for opt in topo-order date-order reflog
 do
 	test_expect_success "show-branch --no-$opt (should fail)" '
 		test_must_fail git show-branch --no-$opt 2>err &&
-		grep "unknown option .no-$opt." err
+		test_grep "unknown option .no-$opt." err
 	'
 done
 

@@ -64,7 +64,7 @@ test_expect_success 'git branch -r shows remote branches' '
 
 test_expect_success 'git branch --no-remotes is rejected' '
 	test_must_fail git branch --no-remotes 2>err &&
-	grep "unknown option .no-remotes." err
+	test_grep "unknown option .no-remotes." err
 '
 
 cat >expect <<'EOF'

@@ -85,7 +85,7 @@ test_expect_success 'git branch -a shows local and remote branches' '
 
 test_expect_success 'git branch --no-all is rejected' '
 	test_must_fail git branch --no-all 2>err &&
-	grep "unknown option .no-all." err
+	test_grep "unknown option .no-all." err
 '
 
 cat >expect <<'EOF'

@@ -538,10 +538,10 @@ do
 			main..unmodified >actual &&
 		test_line_count = 5 actual &&
 		test_grep "^Range-diff:$" 0000-* &&
-		grep "= 1: .* s/5/A" 0000-* &&
-		grep "= 2: .* s/4/A" 0000-* &&
-		grep "= 3: .* s/11/B" 0000-* &&
-		grep "= 4: .* s/12/B" 0000-*
+		test_grep "= 1: .* s/5/A" 0000-* &&
+		test_grep "= 2: .* s/4/A" 0000-* &&
+		test_grep "= 3: .* s/11/B" 0000-* &&
+		test_grep "= 4: .* s/12/B" 0000-*
 	'
 done
 

@@ -564,7 +564,7 @@ test_expect_success 'format-patch --range-diff as commentary' '
 	git format-patch --range-diff=HEAD~1 HEAD~1 >actual &&
 	test_line_count = 1 actual &&
 	test_grep "^Range-diff:$" 0001-* &&
-	grep "> 1: .* new message" 0001-*
+	test_grep "> 1: .* new message" 0001-*
 '
 
 test_expect_success 'format-patch --range-diff reroll-count with a non-integer' '

@@ -572,7 +572,7 @@ test_expect_success 'format-patch --range-diff reroll-count with a non-integer'
 	git format-patch --range-diff=HEAD~1 -v2.9 HEAD~1 >actual &&
 	test_line_count = 1 actual &&
 	test_grep "^Range-diff:$" v2.9-0001-* &&
-	grep "> 1: .* new message" v2.9-0001-*
+	test_grep "> 1: .* new message" v2.9-0001-*
 '
 
 test_expect_success 'format-patch --range-diff reroll-count with a integer' '

@@ -580,7 +580,7 @@ test_expect_success 'format-patch --range-diff reroll-count with a integer' '
 	git format-patch --range-diff=HEAD~1 -v2 HEAD~1 >actual &&
 	test_line_count = 1 actual &&
 	test_grep "^Range-diff ..* v1:$" v2-0001-* &&
-	grep "> 1: .* new message" v2-0001-*
+	test_grep "> 1: .* new message" v2-0001-*
 '
 
 test_expect_success 'format-patch --range-diff with v0' '

@@ -588,7 +588,7 @@ test_expect_success 'format-patch --range-diff with v0' '
 	git format-patch --range-diff=HEAD~1 -v0 HEAD~1 >actual &&
 	test_line_count = 1 actual &&
 	test_grep "^Range-diff:$" v0-0001-* &&
-	grep "> 1: .* new message" v0-0001-*
+	test_grep "> 1: .* new message" v0-0001-*
 '
 
 test_expect_success 'range-diff overrides diff.noprefix internally' '

@@ -686,8 +686,8 @@ test_expect_success 'range-diff with --notes=custom does not show default notes'
 	git notes --ref=custom add -m "unmodified note" unmodified &&
 	git range-diff --notes=custom main..topic main..unmodified \
 		>actual &&
-	! grep "## Notes ##" actual &&
-	grep "## Notes (custom) ##" actual
+	test_grep ! "## Notes ##" actual &&
+	test_grep "## Notes (custom) ##" actual
 '
 
 test_expect_success 'format-patch --range-diff does not compare notes by default' '

@@ -699,12 +699,12 @@ test_expect_success 'format-patch --range-diff does not compare notes by default
 		main..unmodified >actual &&
 	test_line_count = 5 actual &&
 	test_grep "^Range-diff:$" 0000-* &&
-	grep "= 1: .* s/5/A" 0000-* &&
-	grep "= 2: .* s/4/A" 0000-* &&
-	grep "= 3: .* s/11/B" 0000-* &&
-	grep "= 4: .* s/12/B" 0000-* &&
-	! grep "Notes" 0000-* &&
-	! grep "note" 0000-*
+	test_grep "= 1: .* s/5/A" 0000-* &&
+	test_grep "= 2: .* s/4/A" 0000-* &&
+	test_grep "= 3: .* s/11/B" 0000-* &&
+	test_grep "= 4: .* s/12/B" 0000-* &&
+	test_grep ! "Notes" 0000-* &&
+	test_grep ! "note" 0000-*
 '
 
 test_expect_success 'format-patch --notes=custom --range-diff --cover-letter only compares custom notes' '

@@ -717,8 +717,8 @@ test_expect_success 'format-patch --notes=custom --range-diff --cover-letter onl
 	test_when_finished "rm -f 000?-*" &&
 	git format-patch --notes=custom --cover-letter --range-diff=$prev \
 		main..unmodified >actual &&
-	grep "## Notes (custom) ##" 0000-* &&
-	! grep "## Notes ##" 0000-*
+	test_grep "## Notes (custom) ##" 0000-* &&
+	test_grep ! "## Notes ##" 0000-*
 '
 
 # --range-diff on a single commit requires --no-cover-letter

@@ -744,12 +744,12 @@ test_expect_success 'format-patch --range-diff with --no-notes' '
 		main..unmodified >actual &&
 	test_line_count = 5 actual &&
 	test_grep "^Range-diff:$" 0000-* &&
-	grep "= 1: .* s/5/A" 0000-* &&
-	grep "= 2: .* s/4/A" 0000-* &&
-	grep "= 3: .* s/11/B" 0000-* &&
-	grep "= 4: .* s/12/B" 0000-* &&
-	! grep "Notes" 0000-* &&
-	! grep "note" 0000-*
+	test_grep "= 1: .* s/5/A" 0000-* &&
+	test_grep "= 2: .* s/4/A" 0000-* &&
+	test_grep "= 3: .* s/11/B" 0000-* &&
+	test_grep "= 4: .* s/12/B" 0000-* &&
+	test_grep ! "Notes" 0000-* &&
+	test_grep ! "note" 0000-*
 '
 
 test_expect_success 'format-patch --range-diff with --notes' '

@@ -761,10 +761,10 @@ test_expect_success 'format-patch --range-diff with --notes' '
 		main..unmodified >actual &&
 	test_line_count = 5 actual &&
 	test_grep "^Range-diff:$" 0000-* &&
-	grep "= 1: .* s/5/A" 0000-* &&
-	grep "= 2: .* s/4/A" 0000-* &&
-	grep "= 3: .* s/11/B" 0000-* &&
-	grep "! 4: .* s/12/B" 0000-* &&
+	test_grep "= 1: .* s/5/A" 0000-* &&
+	test_grep "= 2: .* s/4/A" 0000-* &&
+	test_grep "= 3: .* s/11/B" 0000-* &&
+	test_grep "! 4: .* s/12/B" 0000-* &&
 	sed s/Z/\ /g >expect <<-EOF &&
 	    @@ Commit message
 	    Z

@@ -790,10 +790,10 @@ test_expect_success 'format-patch --range-diff with format.notes config' '
 		main..unmodified >actual &&
 	test_line_count = 5 actual &&
 	test_grep "^Range-diff:$" 0000-* &&
-	grep "= 1: .* s/5/A" 0000-* &&
-	grep "= 2: .* s/4/A" 0000-* &&
-	grep "= 3: .* s/11/B" 0000-* &&
-	grep "! 4: .* s/12/B" 0000-* &&
+	test_grep "= 1: .* s/5/A" 0000-* &&
+	test_grep "= 2: .* s/4/A" 0000-* &&
+	test_grep "= 3: .* s/11/B" 0000-* &&
+	test_grep "! 4: .* s/12/B" 0000-* &&
 	sed s/Z/\ /g >expect <<-EOF &&
 	    @@ Commit message
 	    Z

@@ -821,10 +821,10 @@ test_expect_success 'format-patch --range-diff with multiple notes' '
 		main..unmodified >actual &&
 	test_line_count = 5 actual &&
 	test_grep "^Range-diff:$" 0000-* &&
-	grep "= 1: .* s/5/A" 0000-* &&
-	grep "= 2: .* s/4/A" 0000-* &&
-	grep "= 3: .* s/11/B" 0000-* &&
-	grep "! 4: .* s/12/B" 0000-* &&
+	test_grep "= 1: .* s/5/A" 0000-* &&
+	test_grep "= 2: .* s/4/A" 0000-* &&
+	test_grep "= 3: .* s/11/B" 0000-* &&
+	test_grep "! 4: .* s/12/B" 0000-* &&
 	sed s/Z/\ /g >expect <<-EOF &&
 	    @@ Commit message
 	    Z

@@ -866,9 +866,9 @@ test_expect_success 'ranges with pathspecs' '
 	topic_oid=$(git rev-parse --short topic) &&
 	mode_change_oid=$(git rev-parse --short mode-only-change^) &&
 	file_change_oid=$(git rev-parse --short mode-only-change) &&
-	grep "$mode_change_oid" actual &&
-	! grep "$file_change_oid" actual &&
-	! grep "$topic_oid" actual
+	test_grep "$mode_change_oid" actual &&
+	test_grep ! "$file_change_oid" actual &&
+	test_grep ! "$topic_oid" actual
 '
 
 test_expect_success 'submodule changes are shown irrespective of diff.submodule' '

@@ -136,7 +136,7 @@ test_expect_success 'should not create any branches if branch is not valid for a
 		git -C sub branch branch-a &&
 		test_must_fail git branch --recurse-submodules branch-a 2>actual &&
 		test_no_branch . branch-a &&
-		grep "submodule .sub.: fatal: a branch named .branch-a. already exists" actual
+		test_grep "submodule .sub.: fatal: a branch named .branch-a. already exists" actual
 	)
 '
 

@@ -251,7 +251,7 @@ test_expect_success 'should get fatal error upon branch creation when submodule
 		git branch --recurse-submodules branch-a origin/branch-a &&
 		# This should fail because super-clone does not have sub2 .git/modules
 		test_must_fail git branch --recurse-submodules branch-b origin/branch-b 2>actual &&
-		grep "fatal: submodule .sub2.: unable to find submodule" actual &&
+		test_grep "fatal: submodule .sub2.: unable to find submodule" actual &&
 		test_no_branch . branch-b &&
 		test_no_branch sub branch-b &&
 		# User can fix themselves by initializing the submodule

@@ -164,7 +164,7 @@ test_expect_success 'show notes' '
 		${indent}b1
 	EOF
 	git cat-file commit HEAD >commits &&
-	! grep b1 commits &&
+	test_grep ! b1 commits &&
 	git log -1 >actual &&
 	test_cmp expect actual
 '

@@ -248,17 +248,17 @@ test_expect_success 'git log --show-notes' '
 
 test_expect_success 'git log --no-notes' '
 	git log -1 --no-notes >actual &&
-	! grep xyzzy actual
+	test_grep ! xyzzy actual
 '
 
 test_expect_success 'git format-patch does not show notes' '
 	git format-patch -1 --stdout >actual &&
-	! grep xyzzy actual
+	test_grep ! xyzzy actual
 '
 
 test_expect_success 'git format-patch --show-notes does show notes' '
 	git format-patch --show-notes -1 --stdout >actual &&
-	grep xyzzy actual
+	test_grep xyzzy actual
 '
 
 for pretty in \

@@ -281,36 +281,36 @@ test_expect_success 'setup alternate notes ref' '
 
 test_expect_success 'git log --notes shows default notes' '
 	git log -1 --notes >actual &&
-	grep xyzzy actual &&
-	! grep alternate actual
+	test_grep xyzzy actual &&
+	test_grep ! alternate actual
 '
 
 test_expect_success 'git log --notes=X shows only X' '
 	git log -1 --notes=alternate >actual &&
-	! grep xyzzy actual &&
-	grep alternate actual
+	test_grep ! xyzzy actual &&
+	test_grep alternate actual
 '
 
 test_expect_success 'git log --notes --notes=X shows both' '
 	git log -1 --notes --notes=alternate >actual &&
-	grep xyzzy actual &&
-	grep alternate actual
+	test_grep xyzzy actual &&
+	test_grep alternate actual
 '
 
 test_expect_success 'git log --no-notes resets default state' '
 	git log -1 --notes --notes=alternate \
 		--no-notes --notes=alternate \
 		>actual &&
-	! grep xyzzy actual &&
-	grep alternate actual
+	test_grep ! xyzzy actual &&
+	test_grep alternate actual
 '
 
 test_expect_success 'git log --no-notes resets ref list' '
 	git log -1 --notes --notes=alternate \
 		--no-notes --notes \
 		>actual &&
-	grep xyzzy actual &&
-	! grep alternate actual
+	test_grep xyzzy actual &&
+	test_grep ! alternate actual
 '
 
 test_expect_success 'show -m notes' '

@@ -543,7 +543,7 @@ test_expect_success 'list notes with "git notes"' '
 
 test_expect_success '"git notes" without subcommand does not take arguments' '
 	test_expect_code 129 git notes HEAD^^ 2>err &&
-	grep "^error: unknown subcommand" err
+	test_grep "^error: unknown subcommand" err
 '
 
 test_expect_success 'list specific note with "git notes list <object>"' '

@@ -1464,7 +1464,7 @@ test_expect_success 'GIT_NOTES_REWRITE_REF overrides config' '
 	GIT_NOTES_REWRITE_REF=refs/notes/commits \
 		git notes copy --for-rewrite=foo <copy &&
 	git log -1 >actual &&
-	grep "replacement note 3" actual
+	test_grep "replacement note 3" actual
 '
 
 test_expect_success 'git notes copy diagnoses too many or too few arguments' '

@@ -382,12 +382,12 @@ EOF
 	test_cmp pre_merge_z actual &&
 	# Merge commit mentions the notes refs merged
 	git log -1 --format=%B refs/notes/m > merge_commit_msg &&
-	grep -q refs/notes/m merge_commit_msg &&
-	grep -q refs/notes/z merge_commit_msg &&
+	test_grep -q refs/notes/m merge_commit_msg &&
+	test_grep -q refs/notes/z merge_commit_msg &&
 	# Merge commit mentions conflicting notes
-	grep -q "Conflicts" merge_commit_msg &&
+	test_grep -q "Conflicts" merge_commit_msg &&
 	( for sha1 in $(cat expect_conflicts); do
-		grep -q "$sha1" merge_commit_msg ||
+		test_grep -q "$sha1" merge_commit_msg ||
 		exit 1
 	done ) &&
 	# Verify contents of merge result

@@ -512,12 +512,12 @@ EOF
 	test_cmp pre_merge_z actual &&
 	# Merge commit mentions the notes refs merged
 	git log -1 --format=%B refs/notes/m > merge_commit_msg &&
-	grep -q refs/notes/m merge_commit_msg &&
-	grep -q refs/notes/z merge_commit_msg &&
+	test_grep -q refs/notes/m merge_commit_msg &&
+	test_grep -q refs/notes/z merge_commit_msg &&
 	# Merge commit mentions conflicting notes
-	grep -q "Conflicts" merge_commit_msg &&
+	test_grep -q "Conflicts" merge_commit_msg &&
 	( for sha1 in $(cat expect_conflicts); do
-		grep -q "$sha1" merge_commit_msg ||
+		test_grep -q "$sha1" merge_commit_msg ||
 		exit 1
 	done ) &&
 	# Verify contents of merge result

@@ -67,7 +67,7 @@ test_expect_success 'merge z into x while mid-merge on y succeeds' '
 		git config core.notesRef refs/notes/x &&
 		test_must_fail git notes merge z >out 2>&1 &&
 		test_grep "Automatic notes merge failed" out &&
-		grep -v "A notes merge into refs/notes/x is already in-progress in" out
+		test_grep -v "A notes merge into refs/notes/x is already in-progress in" out
 	) &&
 	echo "refs/notes/x" >expect &&
 	git -C worktree2 symbolic-ref NOTES_MERGE_REF >actual &&

@@ -287,16 +287,16 @@ test_expect_success 'rebase commit with an ancient timestamp' '
 	git commit --date="@34567 +0600" -m "Old three" &&
 
 	git cat-file commit HEAD^^ >actual &&
-	grep "author .* 12345 +0400$" actual &&
+	test_grep "author .* 12345 +0400$" actual &&
 	git cat-file commit HEAD^ >actual &&
-	grep "author .* 23456 +0500$" actual &&
+	test_grep "author .* 23456 +0500$" actual &&
 	git cat-file commit HEAD >actual &&
-	grep "author .* 34567 +0600$" actual &&
+	test_grep "author .* 34567 +0600$" actual &&
 
 	git rebase --onto HEAD^^ HEAD^ &&
 
 	git cat-file commit HEAD >actual &&
-	grep "author .* 34567 +0600$" actual
+	test_grep "author .* 34567 +0600$" actual
 '
 
 test_expect_success 'rebase with "From " line in commit message' '

@@ -333,7 +333,7 @@ test_expect_success 'rebase --apply and --show-current-patch' '
 		git tag two &&
 		test_must_fail git rebase --apply -f --onto init HEAD^ &&
 		GIT_TRACE=1 git rebase --show-current-patch >/dev/null 2>stderr &&
-		grep "show.*$(git rev-parse two)" stderr
+		test_grep "show.*$(git rev-parse two)" stderr
 	)
 '
 

@@ -364,12 +364,12 @@ test_expect_success 'rebase --apply and .gitattributes' '
 
 		git checkout test &&
 		git rebase main &&
-		grep "smudged" a.txt &&
+		test_grep "smudged" a.txt &&
 
 		git checkout removal &&
 		git reset --hard &&
 		git rebase main &&
-		grep "clean" a.txt
+		test_grep "clean" a.txt
 	)
 '
 

@@ -386,7 +386,7 @@ test_expect_success 'rebase--merge.sh and --show-current-patch' '
 		test_must_fail git rebase --merge --onto init HEAD^ &&
 		git rebase --show-current-patch >actual.patch &&
 		GIT_TRACE=1 git rebase --show-current-patch >/dev/null 2>stderr &&
-		grep "show.*REBASE_HEAD" stderr &&
+		test_grep "show.*REBASE_HEAD" stderr &&
 		test "$(git rev-parse REBASE_HEAD)" = "$(git rev-parse two)"
 	)
 '

@@ -84,8 +84,8 @@ test_expect_success 'rebase -Xtheirs' '
 	echo "AB $T" >> original &&
 	git commit -mconflicting original &&
 	git rebase -Xtheirs main &&
-	grep AB original &&
-	! grep 11 original
+	test_grep AB original &&
+	test_grep ! 11 original
 '
 
 test_expect_success 'rebase -Xtheirs from orphan' '

@@ -93,8 +93,8 @@ test_expect_success 'rebase -Xtheirs from orphan' '
 	echo "AB $T" >> original &&
 	git commit -morphan-conflicting original &&
 	git rebase -Xtheirs main &&
-	grep AB original &&
-	! grep 11 original
+	test_grep AB original &&
+	test_grep ! 11 original
 '
 
 test_expect_success 'merge and rebase should match' '

@@ -210,15 +210,15 @@ test_expect_success '--reapply-cherry-picks refrains from reading unneeded blobs
 	git -C client rev-list --objects --all --missing=print >missing_list &&
 	MERGE_BASE_BLOB=$(git -C server rev-parse main^^:file.txt) &&
 	ADD_11_BLOB=$(git -C server rev-parse main^:file.txt) &&
-	grep "[?]$MERGE_BASE_BLOB" missing_list &&
-	grep "[?]$ADD_11_BLOB" missing_list &&
+	test_grep "[?]$MERGE_BASE_BLOB" missing_list &&
+	test_grep "[?]$ADD_11_BLOB" missing_list &&
 
 	git -C client rebase --merge --reapply-cherry-picks origin/main &&
 
 	# The blob from the merge base had to be fetched, but not "add 11"
 	git -C client rev-list --objects --all --missing=print >missing_list &&
-	! grep "[?]$MERGE_BASE_BLOB" missing_list &&
-	grep "[?]$ADD_11_BLOB" missing_list
+	test_grep ! "[?]$MERGE_BASE_BLOB" missing_list &&
+	test_grep "[?]$ADD_11_BLOB" missing_list
 '
 
 test_done

@@ -144,7 +144,7 @@ test_expect_success 'rebase -i sets work tree properly' '
 	mkdir subdir &&
 	git rebase -x "(cd subdir && git rev-parse --show-toplevel)" HEAD^ \
 		>actual &&
-	! grep "/subdir$" actual
+	test_grep ! "/subdir$" actual
 '
 
 test_expect_success 'rebase -i with the exec command checks tree cleanness' '

@@ -196,7 +196,7 @@ test_expect_success 'rebase -i with exec of inexistent command' '
 		test_must_fail env FAKE_LINES="exec_this-command-does-not-exist 1" \
 			git rebase -i HEAD^ >actual 2>&1
 	) &&
-	! grep "Maybe git-rebase is broken" actual
+	test_grep ! "Maybe git-rebase is broken" actual
 '
 
 test_expect_success 'implicit interactive rebase does not invoke sequence editor' '

@@ -293,7 +293,7 @@ test_expect_success 'stop on conflicting pick' '
 
 test_expect_success 'show conflicted patch' '
 	GIT_TRACE=1 git rebase --show-current-patch >/dev/null 2>stderr &&
-	grep "show.*REBASE_HEAD" stderr &&
+	test_grep "show.*REBASE_HEAD" stderr &&
 	# the original stopped-sha1 is abbreviated
 	stopped_sha1="$(git rev-parse $(cat ".git/rebase-merge/stopped-sha"))" &&
 	test "$(git rev-parse REBASE_HEAD)" = "$stopped_sha1"

@@ -326,7 +326,7 @@ test_expect_success 'retain authorship' '
 	git tag twerp &&
 	git rebase -i --onto primary HEAD^ &&
 	git show HEAD >actual &&
-	grep "^Author: Twerp Snog" actual
+	test_grep "^Author: Twerp Snog" actual
 '
 
 test_expect_success 'retain authorship w/ conflicts' '

@@ -348,7 +348,7 @@ test_expect_success 'retain authorship w/ conflicts' '
 	git rebase --continue &&
 	test_cmp_rev conflict-a^0 HEAD^ &&
 	git show >out &&
-	grep AttributeMe out
+	test_grep AttributeMe out
 '
 
 test_expect_success 'squash' '

@@ -368,7 +368,7 @@ test_expect_success 'squash' '
 
 test_expect_success 'retain authorship when squashing' '
 	git show HEAD >actual &&
-	grep "^Author: Twerp Snog" actual
+	test_grep "^Author: Twerp Snog" actual
 '
 
 test_expect_success '--continue tries to commit' '

@@ -383,7 +383,7 @@ test_expect_success '--continue tries to commit' '
 	) &&
 	test_cmp_rev HEAD^ new-branch1 &&
 	git show HEAD >actual &&
-	grep chouette actual
+	test_grep chouette actual
 '
 
 test_expect_success 'verbose flag is heeded, even after --continue' '

@@ -393,7 +393,7 @@ test_expect_success 'verbose flag is heeded, even after --continue' '
 	echo resolved > file1 &&
 	git add file1 &&
 	git rebase --continue > output &&
-	grep "^ file1 | 2 +-$" output
+	test_grep "^ file1 | 2 +-$" output
 '
 
 test_expect_success 'multi-squash only fires up editor once' '

@@ -422,7 +422,7 @@ test_expect_success 'multi-fixup does not fire up editor' '
 	) &&
 	test $base = $(git rev-parse HEAD^) &&
 	git show >output &&
-	! grep NEVER output &&
+	test_grep ! NEVER output &&
 	git checkout @{-1} &&
 	git branch -D multi-fixup
 '

@@ -487,9 +487,9 @@ test_expect_success 'squash and fixup generate correct log messages' '
 	git cat-file commit HEAD | sed -e 1,/^\$/d > actual-squash-fixup &&
 	test_cmp expect-squash-fixup actual-squash-fixup &&
 	git cat-file commit HEAD@{2} >actual &&
-	grep "^# This is a combination of 3 commits\." actual &&
+	test_grep "^# This is a combination of 3 commits\." actual &&
 	git cat-file commit HEAD@{3} >actual &&
-	grep "^# This is a combination of 2 commits\." actual  &&
+	test_grep "^# This is a combination of 2 commits\." actual  &&
 	git checkout @{-1} &&
 	git branch -D squash-fixup
 '

@@ -593,7 +593,7 @@ test_expect_success '--continue tries to commit, even for "edit"' '
 	) &&
 	test edited = $(git show HEAD:file7) &&
 	git show HEAD >actual &&
-	grep chouette actual &&
+	test_grep chouette actual &&
 	test $parent = $(git rev-parse HEAD^)
 '
 

@@ -779,22 +779,22 @@ test_expect_success 'reword' '
 		FAKE_LINES="1 2 3 reword 4" FAKE_COMMIT_MESSAGE="E changed" \
 			git rebase -i A &&
 		git show HEAD >actual &&
-		grep "E changed" actual &&
+		test_grep "E changed" actual &&
 		test $(git rev-parse primary) != $(git rev-parse HEAD) &&
 		test_cmp_rev primary^ HEAD^ &&
 		FAKE_LINES="1 2 reword 3 4" FAKE_COMMIT_MESSAGE="D changed" \
 			git rebase -i A &&
 		git show HEAD^ >actual &&
-		grep "D changed" actual &&
+		test_grep "D changed" actual &&
 		FAKE_LINES="reword 1 2 3 4" FAKE_COMMIT_MESSAGE="B changed" \
 			git rebase -i A &&
 		git show HEAD~3 >actual &&
-		grep "B changed" actual &&
+		test_grep "B changed" actual &&
 		FAKE_LINES="1 r 2 pick 3 p 4" FAKE_COMMIT_MESSAGE="C changed" \
 			git rebase -i A
 	) &&
 	git show HEAD~2 >actual &&
-	grep "C changed" actual
+	test_grep "C changed" actual
 '
 
 test_expect_success 'reword fast-forwarded empty commit' '

@@ -1043,9 +1043,9 @@ test_expect_success 'rebase -i --root retain root commit author and message' '
 		FAKE_LINES="2" git rebase -i --root
 	) &&
 	git cat-file commit HEAD >output &&
-	grep -q "^author Twerp Snog" output &&
+	test_grep -q "^author Twerp Snog" output &&
 	git cat-file commit HEAD >actual &&
-	grep -q "^different author$" actual
+	test_grep -q "^different author$" actual
 '
 
 test_expect_success 'rebase -i --root temporary sentinel commit' '

@@ -1055,7 +1055,7 @@ test_expect_success 'rebase -i --root temporary sentinel commit' '
 		test_must_fail env FAKE_LINES="2" git rebase -i --root
 	) &&
 	git cat-file commit HEAD >actual &&
-	grep "^tree $EMPTY_TREE" actual &&
+	test_grep "^tree $EMPTY_TREE" actual &&
 	git rebase --abort
 '
 

@@ -1079,7 +1079,7 @@ test_expect_success 'rebase -i --root reword original root commit' '
 			git rebase -i --root
 	) &&
 	git show HEAD^ >actual &&
-	grep "A changed" actual &&
+	test_grep "A changed" actual &&
 	test -z "$(git show -s --format=%p HEAD^)"
 '
 

@@ -1092,7 +1092,7 @@ test_expect_success 'rebase -i --root reword new root commit' '
 		git rebase -i --root
 	) &&
 	git show HEAD^ >actual &&
-	grep "C changed" actual &&
+	test_grep "C changed" actual &&
 	test -z "$(git show -s --format=%p HEAD^)"
 '
 

@@ -1315,11 +1315,11 @@ test_expect_success 'short commit ID collide' '
 		FAKE_COMMIT_MESSAGE="collide2 $(test_oid t3404_collider)" \
 		FAKE_LINES="reword 1 break 2" git rebase -i HEAD~2 &&
 		test $colliding_id = "$(git rev-parse HEAD | cut -c 1-4)" &&
-		grep "^pick $colliding_id " \
+		test_grep "^pick $colliding_id " \
 			.git/rebase-merge/git-rebase-todo.tmp &&
-		grep -E "^pick [0-9a-f]{$hexsz}" \
+		test_grep -E "^pick [0-9a-f]{$hexsz}" \
 			.git/rebase-merge/git-rebase-todo &&
-		grep -E "^pick [0-9a-f]{$hexsz}" \
+		test_grep -E "^pick [0-9a-f]{$hexsz}" \
 			.git/rebase-merge/git-rebase-todo.backup &&
 		git rebase --continue
 	) &&

@@ -1371,7 +1371,7 @@ test_expect_success 'rebase -i commits that overwrite untracked files (pick)' '
 	echo changed >file1 &&
 	git add file1 &&
 	test_must_fail git rebase --continue 2>err &&
-	grep "error: you have staged changes in your working tree" err &&
+	test_grep "error: you have staged changes in your working tree" err &&
 	git reset --hard HEAD &&
 	git rebase --continue &&
 	test_cmp_rev HEAD D &&

@@ -1398,7 +1398,7 @@ test_expect_success 'rebase -i commits that overwrite untracked files (squash)'
 	echo changed >file1 &&
 	git add file1 &&
 	test_must_fail git rebase --continue 2>err &&
-	grep "error: you have staged changes in your working tree" err &&
+	test_grep "error: you have staged changes in your working tree" err &&
 	git reset --hard HEAD &&
 	git rebase --continue &&
 	test $(git cat-file commit HEAD | sed -ne \$p) = I &&

@@ -1423,7 +1423,7 @@ test_expect_success 'rebase -i commits that overwrite untracked files (no ff)' '
 	echo changed >file1 &&
 	git add file1 &&
 	test_must_fail git rebase --continue 2>err &&
-	grep "error: you have staged changes in your working tree" err &&
+	test_grep "error: you have staged changes in your working tree" err &&
 	git reset --hard HEAD &&
 	git rebase --continue &&
 	test $(git cat-file commit HEAD | sed -ne \$p) = I

@@ -1709,15 +1709,15 @@ test_expect_success 'the first command cannot be a fixup' '
 		set_replace_editor orig &&
 		test_must_fail git rebase -i A 2>actual
 	) &&
-	grep "cannot .fixup. without a previous commit" actual &&
-	grep "You can fix this with .git rebase --edit-todo.." actual &&
+	test_grep "cannot .fixup. without a previous commit" actual &&
+	test_grep "You can fix this with .git rebase --edit-todo.." actual &&
 	# verify that the todo list has not been truncated
 	grep -v "^#" .git/rebase-merge/git-rebase-todo >actual &&
 	test_cmp orig actual &&
 
 	test_must_fail git rebase --edit-todo 2>actual &&
-	grep "cannot .fixup. without a previous commit" actual &&
-	grep "You can fix this with .git rebase --edit-todo.." actual &&
+	test_grep "cannot .fixup. without a previous commit" actual &&
+	test_grep "You can fix this with .git rebase --edit-todo.." actual &&
 	# verify that the todo list has not been truncated
 	grep -v "^#" .git/rebase-merge/git-rebase-todo >actual &&
 	test_cmp orig actual

@@ -2252,7 +2252,7 @@ test_expect_success '--update-refs: check failed ref update' '
 	git update-ref refs/heads/second third &&
 
 	test_must_fail git rebase --continue 2>err &&
-	grep "update_ref failed for ref '\''refs/heads/second'\''" err &&
+	test_grep "update_ref failed for ref '\''refs/heads/second'\''" err &&
 
 	q_to_tab >expect <<-\EOF &&
 	Updated the following refs with --update-refs:

@@ -2283,10 +2283,10 @@ test_expect_success 'bad labels and refs rejected when parsing todo list' '
 		set_replace_editor todo &&
 		test_must_fail git rebase -i HEAD 2>err
 	) &&
-	grep "'\''#'\'' is not a valid label" err &&
-	grep "'\'':invalid'\'' is not a valid label" err &&
-	grep "'\'':bad'\'' is not a valid refname" err &&
-	grep "update-ref requires a fully qualified refname e.g. refs/heads/topic" \
+	test_grep "'\''#'\'' is not a valid label" err &&
+	test_grep "'\'':invalid'\'' is not a valid label" err &&
+	test_grep "'\'':bad'\'' is not a valid refname" err &&
+	test_grep "update-ref requires a fully qualified refname e.g. refs/heads/topic" \
 		err &&
 	test_path_is_missing execed
 '

@@ -62,21 +62,21 @@ test_expect_success 'rebase fast-forward to main' '
 test_expect_success 'rebase --stat' '
 	git reset --hard start &&
 	git rebase --stat main >diffstat.txt &&
-	grep "^ fileX |  *1 +$" diffstat.txt
+	test_grep "^ fileX |  *1 +$" diffstat.txt
 '
 
 test_expect_success 'rebase w/config rebase.stat' '
 	git reset --hard start &&
 	git config rebase.stat true &&
 	git rebase main >diffstat.txt &&
-	grep "^ fileX |  *1 +$" diffstat.txt
+	test_grep "^ fileX |  *1 +$" diffstat.txt
 '
 
 test_expect_success 'rebase -n overrides config rebase.stat config' '
 	git reset --hard start &&
 	git config rebase.stat true &&
 	git rebase -n main >diffstat.txt &&
-	! grep "^ fileX |  *1 +$" diffstat.txt
+	test_grep ! "^ fileX |  *1 +$" diffstat.txt
 '
 
 test_expect_success 'rebase --onto outputs the invalid ref' '

@@ -223,7 +223,7 @@ test_expect_success 'auto squash that matches a sha1' '
 	git cat-file blob HEAD^:file1 >actual &&
 	test_cmp expect actual &&
 	git cat-file commit HEAD^ >commit &&
-	! grep "squash" commit &&
+	test_grep ! "squash" commit &&
 	grep "^extra para" commit >actual &&
 	test_line_count = 1 actual
 '

@@ -245,7 +245,7 @@ test_expect_success 'auto squash that matches longer sha1' '
 	git cat-file blob HEAD^:file1 >actual &&
 	test_cmp expect actual &&
 	git cat-file commit HEAD^ >commit &&
-	! grep "squash" commit &&
+	test_grep ! "squash" commit &&
 	grep "^extra para" commit >actual &&
 	test_line_count = 1 actual
 '

@@ -377,7 +377,7 @@ test_expect_success 'autosquash with custom inst format' '
 	git cat-file blob HEAD^:file1 >actual &&
 	test_cmp expect actual &&
 	git cat-file commit HEAD^ >commit &&
-	! grep "squash" commit &&
+	test_grep ! "squash" commit &&
 	grep first commit >actual &&
 	test_line_count = 3 actual
 '

@@ -424,7 +424,7 @@ test_expect_success 'autosquash with multiple empty patches' '
 		set_backup_editor &&
 		GIT_USE_REBASE_HELPER=false \
 		git rebase -i --force-rebase --autosquash HEAD~4 &&
-		grep empty2 .git/backup-git-rebase-todo
+		test_grep empty2 .git/backup-git-rebase-todo
 	)
 '
 

@@ -467,7 +467,7 @@ test_expect_success 'abort last squash' '
 	git commit --allow-empty --amend -m edited-first &&
 	git rebase --skip &&
 	git show >actual &&
-	! grep first actual
+	test_grep ! first actual
 '
 
 test_expect_success 'fixup a fixup' '

@@ -107,7 +107,7 @@ test_expect_success 'rebase --onto main...side requires a single merge-base' '
 	git reset --hard K &&
 
 	test_must_fail git rebase -i --onto main...side J 2>err &&
-	grep "need exactly one merge base" err
+	test_grep "need exactly one merge base" err
 '
 
 test_expect_success 'rebase --keep-base --onto incompatible' '

@@ -196,7 +196,7 @@ test_expect_success 'rebase --keep-base requires a single merge base' '
 	git reset --hard K &&
 
 	test_must_fail git rebase -i --keep-base main 2>err &&
-	grep "need exactly one merge base with branch" err
+	test_grep "need exactly one merge base with branch" err
 '
 
 test_expect_success 'rebase --keep-base keeps cherry picks' '

@@ -289,18 +289,18 @@ test_expect_success 'patch file is removed before break command' '
 test_expect_success '--reschedule-failed-exec' '
 	test_when_finished "git rebase --abort" &&
 	test_must_fail git rebase -x false --reschedule-failed-exec HEAD^ &&
-	grep "^exec false" .git/rebase-merge/git-rebase-todo &&
+	test_grep "^exec false" .git/rebase-merge/git-rebase-todo &&
 	git rebase --abort &&
 	test_must_fail git -c rebase.rescheduleFailedExec=true \
 		rebase -x false HEAD^ 2>err &&
-	grep "^exec false" .git/rebase-merge/git-rebase-todo &&
+	test_grep "^exec false" .git/rebase-merge/git-rebase-todo &&
 	test_grep "has been rescheduled" err
 '
 
 test_expect_success 'rebase.rescheduleFailedExec only affects `rebase -i`' '
 	test_config rebase.rescheduleFailedExec true &&
 	test_must_fail git rebase -x false HEAD^ &&
-	grep "^exec false" .git/rebase-merge/git-rebase-todo &&
+	test_grep "^exec false" .git/rebase-merge/git-rebase-todo &&
 	git rebase --abort &&
 	git rebase HEAD^
 '

@@ -310,7 +310,7 @@ test_expect_success 'rebase.rescheduleFailedExec=true & --no-reschedule-failed-e
 	test_config rebase.rescheduleFailedExec true &&
 	test_must_fail git rebase -x false --no-reschedule-failed-exec HEAD~2 &&
 	test_must_fail git rebase --continue 2>err &&
-	! grep "has been rescheduled" err
+	test_grep ! "has been rescheduled" err
 '
 
 test_expect_success 'new rebase.rescheduleFailedExec=true setting in an ongoing rebase is ignored' '

@@ -318,7 +318,7 @@ test_expect_success 'new rebase.rescheduleFailedExec=true setting in an ongoing
 	test_must_fail git rebase -x false HEAD~2 &&
 	test_config rebase.rescheduleFailedExec true &&
 	test_must_fail git rebase --continue 2>err &&
-	! grep "has been rescheduled" err
+	test_grep ! "has been rescheduled" err
 '
 
 test_expect_success 'there is no --no-reschedule-failed-exec in an ongoing rebase' '

@@ -141,8 +141,8 @@ testrebase () {
 		git checkout -b rebased-feature-branch feature-branch &&
 		echo dirty >>file3 &&
 		git rebase$type unrelated-onto-branch >actual 2>&1 &&
-		grep unrelated file4 &&
-		grep dirty file3 &&
+		test_grep unrelated file4 &&
+		test_grep dirty file3 &&
 		git checkout feature-branch
 	'
 

@@ -165,8 +165,8 @@ testrebase () {
 		echo dirty >>file3 &&
 		git add file3 &&
 		git rebase$type unrelated-onto-branch &&
-		grep unrelated file4 &&
-		grep dirty file3 &&
+		test_grep unrelated file4 &&
+		test_grep dirty file3 &&
 		git checkout feature-branch
 	'
 

@@ -197,7 +197,7 @@ testrebase () {
 		git add file2 &&
 		git rebase --continue &&
 		test_path_is_missing $dotest/autostash &&
-		grep dirty file3 &&
+		test_grep dirty file3 &&
 		git checkout feature-branch
 	'
 

@@ -212,7 +212,7 @@ testrebase () {
 		test_path_is_missing file3 &&
 		git rebase --skip &&
 		test_path_is_missing $dotest/autostash &&
-		grep dirty file3 &&
+		test_grep dirty file3 &&
 		git checkout feature-branch
 	'
 

@@ -227,7 +227,7 @@ testrebase () {
 		test_path_is_missing file3 &&
 		git rebase --abort &&
 		test_path_is_missing $dotest/autostash &&
-		grep dirty file3 &&
+		test_grep dirty file3 &&
 		git checkout feature-branch
 	'
 

@@ -260,11 +260,11 @@ testrebase () {
 		git rebase$type unrelated-onto-branch >actual 2>&1 &&
 		test_path_is_missing $dotest &&
 		git reset --hard &&
-		grep unrelated file4 &&
-		! grep dirty file4 &&
+		test_grep unrelated file4 &&
+		test_grep ! dirty file4 &&
 		git checkout feature-branch &&
 		git stash pop &&
-		grep dirty file4
+		test_grep dirty file4
 	'
 
 	test_expect_success "rebase$type: check output with conflicting stash" '

@@ -286,7 +286,7 @@ test_expect_success "rebase: fast-forward rebase" '
 	test_when_finished git branch -D behind-feature-branch &&
 	echo dirty >>file1 &&
 	git rebase feature-branch &&
-	grep dirty file1 &&
+	test_grep dirty file1 &&
 	git checkout feature-branch
 '
 

@@ -297,7 +297,7 @@ test_expect_success "rebase: noop rebase" '
 	test_when_finished git branch -D same-feature-branch &&
 	echo dirty >>file1 &&
 	git rebase feature-branch &&
-	grep dirty file1 &&
+	test_grep dirty file1 &&
 	git checkout feature-branch
 '
 

@@ -102,13 +102,13 @@ test_rebase_am_only () {
 	test_expect_success "$opt incompatible with rebase.rebaseMerges" "
 		git checkout B^0 &&
 		test_must_fail git -c rebase.rebaseMerges=true rebase $opt A 2>err &&
-		grep -e --no-rebase-merges err
+		test_grep -e --no-rebase-merges err
 	"
 
 	test_expect_success "$opt incompatible with rebase.updateRefs" "
 		git checkout B^0 &&
 		test_must_fail git -c rebase.updateRefs=true rebase $opt A 2>err &&
-		grep -e --no-update-refs err
+		test_grep -e --no-update-refs err
 	"
 
 	test_expect_success "$opt okay with overridden rebase.rebaseMerges" "

@@ -19,7 +19,7 @@ test_expect_success 'rebase exec modifies rebase-todo' '
 
 test_expect_success 'rebase exec with an empty list does not exec anything' '
 	git rebase HEAD -x "true" 2>output &&
-	! grep "Executing: true" output
+	test_grep ! "Executing: true" output
 '
 
 test_expect_success 'loose object cache vs re-reading todo list' '

@@ -161,7 +161,7 @@ test_expect_success '`reset` rejects trees' '
 	test_when_finished "test_might_fail git rebase --abort" &&
 	test_must_fail env GIT_SEQUENCE_EDITOR="echo reset A^{tree} >" \
 		git rebase -i B C >out 2>err &&
-	grep "object .* is a tree" err &&
+	test_grep "object .* is a tree" err &&
 	test_must_be_empty out
 '
 

@@ -170,7 +170,7 @@ test_expect_success '`reset` only looks for labels under refs/rewritten/' '
 	git branch refs/rewritten/my-label A &&
 	test_must_fail env GIT_SEQUENCE_EDITOR="echo reset my-label >" \
 		git rebase -i B C >out 2>err &&
-	grep "could not resolve ${SQ}my-label${SQ}" err &&
+	test_grep "could not resolve ${SQ}my-label${SQ}" err &&
 	test_must_be_empty out
 '
 

@@ -185,18 +185,18 @@ test_expect_success 'failed `merge -C` writes patch (may be rescheduled, too)' '
 	test_tick &&
 	test_must_fail git rebase -ir HEAD &&
 	test_cmp_rev REBASE_HEAD H^0 &&
-	grep "^merge -C .* G$" .git/rebase-merge/done &&
-	grep "^merge -C .* G$" .git/rebase-merge/git-rebase-todo &&
+	test_grep "^merge -C .* G$" .git/rebase-merge/done &&
+	test_grep "^merge -C .* G$" .git/rebase-merge/git-rebase-todo &&
 	test_path_is_missing .git/rebase-merge/patch &&
 	echo changed >file1 &&
 	git add file1 &&
 	test_must_fail git rebase --continue 2>err &&
-	grep "error: you have staged changes in your working tree" err &&
+	test_grep "error: you have staged changes in your working tree" err &&
 
 	: fail because of merge conflict &&
 	git reset --hard conflicting-G &&
 	test_must_fail git rebase --continue &&
-	! grep "^merge -C .* G$" .git/rebase-merge/git-rebase-todo &&
+	test_grep ! "^merge -C .* G$" .git/rebase-merge/git-rebase-todo &&
 	test_path_is_file .git/rebase-merge/patch
 '
 

@@ -208,8 +208,8 @@ test_expect_success 'failed `merge <branch>` does not crash' '
 	test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
 	test_tick &&
 	test_must_fail git rebase -ir HEAD &&
-	! grep "^merge G$" .git/rebase-merge/git-rebase-todo &&
-	grep "^Merge branch ${SQ}G${SQ}$" .git/rebase-merge/message
+	test_grep ! "^merge G$" .git/rebase-merge/git-rebase-todo &&
+	test_grep "^Merge branch ${SQ}G${SQ}$" .git/rebase-merge/message
 '
 
 test_expect_success 'merge -c commits before rewording and reloads todo-list' '

@@ -481,8 +481,8 @@ test_expect_success 'labels that are object IDs are rewritten' '
 	test_config sequence.editor \""$PWD"/replace-editor.sh\" &&
 	test_tick &&
 	git rebase -i -r A &&
-	grep "^label $third-" .git/ORIGINAL-TODO &&
-	! grep "^label $third$" .git/ORIGINAL-TODO
+	test_grep "^label $third-" .git/ORIGINAL-TODO &&
+	test_grep ! "^label $third$" .git/ORIGINAL-TODO
 '
 
 test_expect_success 'octopus merges' '