[PATCHv2] builtin/merge: honor commit-msg hook for merges

From

Stefan Beller <sbeller@google.com>

Date

Sep 5, 2017, 23:29 UTC

Message-ID

<20170905232953.22330-1-sbeller@google.com>

In-Reply-To

<xmqqd174bzco.fsf@gitster.mtv.corp.google.com>

Signed-off-by: Stefan Beller <sbeller@google.com>
---

addressed all but one issues.

Junio writes:

> I didn't check how "merge --continue" is implemented, but we need to
> behave exactly the same way over there, too.  Making sure that it is
> a case in t7504 may be a good idea, in addition to the test you
> added.

After inspection of the code I do not think it is a good idea, because
(a) it clutters the test suite with something "obvious" for now,
    the call to cmd_commit will be the same as git-commit on the
    command line and
(b) piping through --[no-]verify would either introduce irregularities
    ("Why do we pipe through --no-verify, when --sign-off is more important?")
    or miss important options to pipe through: 

	static int continue_current_merge;
...
	OPT_BOOL(0, "continue", &continue_current_merge,
		N_("continue the current in-progress merge")),
...
	if (continue_current_merge) {
		int nargc = 1;
		const char *nargv[] = {"commit", NULL};

		if (orig_argc != 2)
			usage_msg_opt(_("--continue expects no arguments"),
			      builtin_merge_usage, builtin_merge_options);

		/* Invoke 'git commit' */
		ret = cmd_commit(nargc, nargv, prefix);
		goto done;
	}

 builtin/merge.c            |  8 ++++++++
 t/t7504-commit-msg-hook.sh | 45 +++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/builtin/merge.c b/builtin/merge.c
index 7df3fe3927..780435d7a1 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -73,6 +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 struct strategy all_strategy[] = {
 	{ "recursive",  DEFAULT_TWOHEAD | NO_TRIVIAL },
@@ -236,6 +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_END()
 };
 
@@ -780,6 +782,12 @@ static void prepare_to_commit(struct commit_list *remoteheads)
 		if (launch_editor(git_path_merge_msg(), NULL, NULL))
 			abort_commit(remoteheads, NULL);
 	}
+
+	if (verify_msg && run_commit_hook(0 < option_edit, get_index_file(),
+					  "commit-msg",
+					  git_path_merge_msg(), NULL))
+		abort_commit(remoteheads, NULL);
+
 	read_merge_msg(&msg);
 	strbuf_stripspace(&msg, 0 < option_edit);
 	if (!msg.len)
diff --git a/t/t7504-commit-msg-hook.sh b/t/t7504-commit-msg-hook.sh
index 88d4cda299..1cd54af3cc 100755
--- a/t/t7504-commit-msg-hook.sh
+++ b/t/t7504-commit-msg-hook.sh
@@ -101,6 +101,10 @@ cat > "$HOOK" <<EOF
 exit 1
 EOF
 
+commit_msg_is () {
+	test "$(git log --pretty=format:%s%b -1)" = "$1"
+}
+
 test_expect_success 'with failing hook' '
 
 	echo "another" >> file &&
@@ -135,6 +139,32 @@ test_expect_success '--no-verify with failing hook (editor)' '
 
 '
 
+test_expect_success 'merge fails with failing hook' '
+
+	test_when_finished "git branch -D newbranch" &&
+	test_when_finished "git checkout -f master" &&
+	git checkout --orphan newbranch &&
+	: >file2 &&
+	git add file2 &&
+	git commit --no-verify file2 -m in-side-branch &&
+	test_must_fail git merge --allow-unrelated-histories master &&
+	commit_msg_is "in-side-branch" # HEAD before merge
+
+'
+
+test_expect_success 'merge bypasses failing hook with --no-verify' '
+
+	test_when_finished "git branch -D newbranch" &&
+	test_when_finished "git checkout -f master" &&
+	git checkout --orphan newbranch &&
+	: >file2 &&
+	git add file2 &&
+	git commit --no-verify file2 -m in-side-branch &&
+	git merge --no-verify --allow-unrelated-histories master &&
+	commit_msg_is "Merge branch '\''master'\'' into newbranch"
+'
+
+
 chmod -x "$HOOK"
 test_expect_success POSIXPERM 'with non-executable hook' '
 
@@ -178,10 +208,6 @@ exit 0
 EOF
 chmod +x "$HOOK"
 
-commit_msg_is () {
-	test "$(git log --pretty=format:%s%b -1)" = "$1"
-}
-
 test_expect_success 'hook edits commit message' '
 
 	echo "additional" >> file &&
@@ -217,7 +243,17 @@ test_expect_success "hook doesn't edit commit message (editor)" '
 	echo "more plus" > FAKE_MSG &&
 	GIT_EDITOR="\"\$FAKE_EDITOR\"" git commit --no-verify &&
 	commit_msg_is "more plus"
+'
 
+test_expect_success 'hook called in git-merge picks up commit message' '
+	test_when_finished "git branch -D newbranch" &&
+	test_when_finished "git checkout -f master" &&
+	git checkout --orphan newbranch &&
+	: >file2 &&
+	git add file2 &&
+	git commit --no-verify file2 -m in-side-branch &&
+	git merge --allow-unrelated-histories master &&
+	commit_msg_is "new message"
 '
 
 # set up fake editor to replace `pick` by `reword`
@@ -237,4 +273,5 @@ test_expect_success 'hook is called for reword during `rebase -i`' '
 
 '
 
+
 test_done

-- 
2.14.0.rc0.3.g6c2e499285