commit -v: strip diffs and submodule shortlogs from the commit message

When using the '-v' option of "git commit" the diff added to the commit
message temporarily for editing is stripped off after the user exited the
editor by searching for "\ndiff --git " and truncating the commmit message
there if it is found.

But this approach has two problems:

- when the commit message itself contains a line starting with
  "diff --git" it will be truncated there prematurely; and

- when the "diff.submodule" setting is set to "log", the diff may
  start with "Submodule <hash1>..<hash2>", which will be left in
  the commit message while it shouldn't.

Fix that by introducing a special scissor separator line starting with the
comment character ('#' or the core.commentChar config if set) followed by
two lines describing what it is for. The scissor line - which will not be
translated - is used to reliably detect the start of the diff so it can be
chopped off from the commit message, no matter what the user enters there.

Turn a known test failure fixed by this change into a successful test;
also add one for a diff starting with a submodule log and another one for
proper handling of the comment char.

Reported-by: Ari Pollak <ari@debian.org>
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 27 insertions, 1 deletions

diff --git a/t/t7507-commit-verbose.sh b/t/t7507-commit-verbose.sh
index da5bd3b..2ddf28c 100755
--- a/t/t7507-commit-verbose.sh
+++ b/t/t7507-commit-verbose.sh
@@ -65,9 +65,35 @@ test_expect_success 'diff in message is retained without -v' '
 	check_message diff
 '
 
-test_expect_failure 'diff in message is retained with -v' '
+test_expect_success 'diff in message is retained with -v' '
 	git commit --amend -F diff -v &&
 	check_message diff
 '
 
+test_expect_success 'submodule log is stripped out too with -v' '
+	git config diff.submodule log &&
+	git submodule add ./. sub &&
+	git commit -m "sub added" &&
+	(
+		cd sub &&
+		echo "more" >>file &&
+		git commit -a -m "submodule commit"
+	) &&
+	(
+		GIT_EDITOR=cat &&
+		export GIT_EDITOR &&
+		test_must_fail git commit -a -v 2>err
+	) &&
+	test_i18ngrep "Aborting commit due to empty commit message." err
+'
+
+test_expect_success 'verbose diff is stripped out with set core.commentChar' '
+	(
+		GIT_EDITOR=cat &&
+		export GIT_EDITOR &&
+		test_must_fail git -c core.commentchar=";" commit -a -v 2>err
+	) &&
+	test_i18ngrep "Aborting commit due to empty commit message." err
+'
+
 test_done