[PATCH 0/4] pre-merge hook

@@ -73,7 +73,7 @@ static int show_progress = -1;
 static int default_to_upstream = 1;
 static int signoff;
 static const char *sign_commit;
-static int verify_msg = 1;
+static int no_verify;
 
 static struct strategy all_strategy[] = {
 	{ "recursive",  DEFAULT_TWOHEAD | NO_TRIVIAL },

@@ -237,7 +237,7 @@ static struct option builtin_merge_options[] = {
 	  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 	OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
 	OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
-	OPT_BOOL(0, "verify", &verify_msg, N_("verify commit-msg hook")),
+	OPT_BOOL(0, "no-verify", &no_verify, N_("bypass commit-msg hook")),
 	OPT_END()
 };
 

@@ -798,7 +798,7 @@ static void prepare_to_commit(struct commit_list *remoteheads)
 			abort_commit(remoteheads, NULL);
 	}
 
-	if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
+	if (!no_verify && run_commit_hook(0 < option_edit, get_index_file(),
 					  "commit-msg",
 					  git_path_merge_msg(), NULL))
 		abort_commit(remoteheads, NULL);

@@ -99,6 +99,13 @@ All the 'git commit' hooks are invoked with the environment
 variable `GIT_EDITOR=:` if the command will not bring up an editor
 to modify the commit message.
 
+pre-merge
+~~~~~~~~~
+
+This hook is invoked by 'git merge' when doing an automatic merge
+commit; it is equivalent to 'pre-commit' for a non-automatic commit
+for a merge.
+
 prepare-commit-msg
 ~~~~~~~~~~~~~~~~~~
 

@@ -769,6 +769,17 @@ static void write_merge_heads(struct commit_list *);
 static void prepare_to_commit(struct commit_list *remoteheads)
 {
 	struct strbuf msg = STRBUF_INIT;
+	const char *index_file = get_index_file();
+
+	if (run_commit_hook(0 < option_edit, index_file, "pre-merge", NULL))
+		abort_commit(remoteheads, NULL);
+	/*
+	 * Re-read the index as pre-merge hook could have updated it,
+	 * and write it out as a tree.  We must do this before we invoke
+	 * the editor and after we invoke run_status above.
+	 */
+	discard_cache();
+	read_cache_from(index_file);
 	strbuf_addbuf(&msg, &merge_msg);
 	strbuf_addch(&msg, '\n');
 	if (squash)

@@ -0,0 +1,13 @@
+#!/bin/sh
+#
+# An example hook script to verify what is about to be committed.
+# Called by "git merge" with no arguments.  The hook should
+# exit with non-zero status after issuing an appropriate message if
+# it wants to stop the commit.
+#
+# To enable this hook, rename this file to "pre-merge".
+
+. git-sh-setup
+test -x "$GIT_DIR/hooks/pre-commit" &&
+        exec "$GIT_DIR/hooks/pre-commit"
+:

@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git merge' [-n] [--stat] [--no-commit] [--squash] [--[no-]edit]
-	[-s <strategy>] [-X <strategy-option>] [-S[<keyid>]]
+	[--no-verify] [-s <strategy>] [-X <strategy-option>] [-S[<keyid>]]
 	[--[no-]allow-unrelated-histories]
 	[--[no-]rerere-autoupdate] [-m <msg>] [<commit>...]
 'git merge' --abort

@@ -104,7 +104,7 @@ pre-merge
 
 This hook is invoked by 'git merge' when doing an automatic merge
 commit; it is equivalent to 'pre-commit' for a non-automatic commit
-for a merge.
+for a merge, and can be bypassed with the `--no-verify` option. 
 
 prepare-commit-msg
 ~~~~~~~~~~~~~~~~~~

@@ -74,6 +74,10 @@ merge.
 With --no-squash perform the merge and commit the result. This
 option can be used to override --squash.
 
+--no-verify::
+	This option bypasses the pre-merge and commit-msg hooks.
+	See also linkgit:githooks[5].
+
 -s <strategy>::
 --strategy=<strategy>::
 	Use the given merge strategy; can be supplied more than

@@ -237,7 +237,7 @@ static struct option builtin_merge_options[] = {
 	  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 	OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
 	OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
-	OPT_BOOL(0, "no-verify", &no_verify, N_("bypass commit-msg hook")),
+	OPT_BOOL(0, "no-verify", &no_verify, N_("bypass pre-merge and commit-msg hooks")),
 	OPT_END()
 };
 

@@ -771,7 +771,7 @@ static void prepare_to_commit(struct commit_list *remoteheads)
 	struct strbuf msg = STRBUF_INIT;
 	const char *index_file = get_index_file();
 
-	if (run_commit_hook(0 < option_edit, index_file, "pre-merge", NULL))
+	if (!no_verify && run_commit_hook(0 < option_edit, index_file, "pre-merge", NULL))
 		abort_commit(remoteheads, NULL);
 	/*
 	 * Re-read the index as pre-merge hook could have updated it,

@@ -1,9 +1,22 @@
 #!/bin/sh
 
-test_description='pre-commit hook'
+test_description='pre-commit and pre-merge hooks'
 
 . ./test-lib.sh
 
+test_expect_success 'root commit' '
+
+	echo "root" > file &&
+	git add file &&
+	git commit -m "zeroth" &&
+	git checkout -b side &&
+	echo "foo" > foo &&
+	git add foo &&
+	git commit -m "make it non-ff" &&
+	git checkout master
+
+'
+
 test_expect_success 'with no hook' '
 
 	echo "foo" > file &&

@@ -12,6 +25,14 @@ test_expect_success 'with no hook' '
 
 '
 
+test_expect_success 'with no hook (merge)' '
+
+	git checkout side &&
+	git merge -m "merge master" master &&
+	git checkout master
+
+'
+
 test_expect_success '--no-verify with no hook' '
 
 	echo "bar" > file &&

@@ -20,15 +41,25 @@ test_expect_success '--no-verify with no hook' '
 
 '
 
+test_expect_success '--no-verify with no hook (merge)' '
+
+	git checkout side &&
+	git merge --no-verify -m "merge master" master &&
+	git checkout master
+
+'
+
 # now install hook that always succeeds
 HOOKDIR="$(git rev-parse --git-dir)/hooks"
 HOOK="$HOOKDIR/pre-commit"
+MERGEHOOK="$HOOKDIR/pre-merge"
 mkdir -p "$HOOKDIR"
 cat > "$HOOK" <<EOF
 #!/bin/sh
 exit 0
 EOF
 chmod +x "$HOOK"
+cp -p "$HOOK" "$MERGEHOOK"
 
 test_expect_success 'with succeeding hook' '
 

@@ -38,6 +69,14 @@ test_expect_success 'with succeeding hook' '
 
 '
 
+test_expect_success 'with succeeding hook (merge)' '
+
+	git checkout side &&
+	git merge -m "merge master" master &&
+	git checkout master
+
+'
+
 test_expect_success '--no-verify with succeeding hook' '
 
 	echo "even more" >> file &&

@@ -46,11 +85,20 @@ test_expect_success '--no-verify with succeeding hook' '
 
 '
 
+test_expect_success '--no-verify with succeeding hook (merge)' '
+
+	git checkout side &&
+	git merge --no-verify -m "merge master" master &&
+	git checkout master
+
+'
+
 # now a hook that fails
 cat > "$HOOK" <<EOF
 #!/bin/sh
 exit 1
 EOF
+cp -p "$HOOK" "$MERGEHOOK"
 
 test_expect_success 'with failing hook' '
 

@@ -68,6 +116,22 @@ test_expect_success '--no-verify with failing hook' '
 
 '
 
+test_expect_success 'with failing hook (merge)' '
+
+	git checkout side &&
+	test_must_fail git merge -m "merge master" master &&
+	git checkout master
+
+'
+
+test_expect_success '--no-verify with failing hook (merge)' '
+
+	git checkout side &&
+	git merge --no-verify -m "merge master" master &&
+	git checkout master
+
+'
+
 chmod -x "$HOOK"
 test_expect_success POSIXPERM 'with non-executable hook' '