Re: [PATCH 04/11] t3030-merge-recursive: don't check the stderr of a subshell

SZEDER Gábor [off-list ref] writes:

The two test checking 'git mmerge-recursive' in an empty worktree in
...
 		GIT_INDEX_FILE="$PWD/ours-has-rename-index" &&
 		export GIT_INDEX_FILE &&
 		mkdir "$GIT_WORK_TREE" &&
-		git read-tree -i -m $c7 &&
-		git update-index --ignore-missing --refresh &&
-		git merge-recursive $c0 -- $c7 $c3 &&
-		git ls-files -s >actual-files
-	) 2>actual-err &&
-	>expected-err &&
+		git read-tree -i -m $c7 2>actual-err &&
+		test_must_be_empty expected-err &&
+		git update-index --ignore-missing --refresh 2>actual-err &&
+		test_must_be_empty expected-err &&
+		git merge-recursive $c0 -- $c7 $c3 2>actual-err &&
+		test_must_be_empty expected-err &&
+		git ls-files -s >actual-files 2>actual-err &&
+		test_must_be_empty expected-err

Where do the contents of all of these expected-err files come from?
Should all of the test_must_be_empty checks be checking actual-err
instead?