[PATCH 2/2] commit: inform pre-commit that --amend was used

From: Øystein Walle <oystwa@gmail.com>
Date: Nov 25, 2014, 22:51 UTC
Message-ID: <b9ef551633329702559e4cee6528b68ab757b531.1416955873.git.oystwa@gmail.com>
In-Reply-To: <cover.1416953772.git.oystwa@gmail.com>

When a commit is amended a pre-commit hook that verifies the commit's contents might not find what it's looking for if it looks at the differences against HEAD when HEAD~1 might be more appropriate. Inform the commit hook that --amend is being used so that hook authors can do e.g.

    if test "$1" = amend; then
        ...
    else
        ...
    fi

to handle these situations.

Signed-off-by: Øystein Walle <oystwa@gmail.com>
---
 Documentation/githooks.txt |  3 ++-
 builtin/commit.c           |  3 ++-
 t/t7503-pre-commit-hook.sh | 11 +++++++++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/Documentation/githooks.txt b/Documentation/githooks.txt
index 9ef2469..fb3e71e 100644
--- a/Documentation/githooks.txt
+++ b/Documentation/githooks.txt
@@ -73,7 +73,8 @@ pre-commit
 ~~~~~~~~~~
 
 This hook is invoked by 'git commit', and can be bypassed
-with `--no-verify` option.  It takes no parameter, and is
+with `--no-verify` option.  It takes one parameter which is "amend" if
+`--amend` was used when committing and "noamend" if not. It is
 invoked before obtaining the proposed commit log message and
 making a commit.  Exiting with non-zero status from this script
 causes the 'git commit' to abort.
diff --git a/builtin/commit.c b/builtin/commit.c
index e108c53..f9e5d27 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -694,7 +694,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	/* This checks and barfs if author is badly specified */
 	determine_author_info(author_ident);
 
-	if (!no_verify && run_commit_hook(use_editor, index_file, "pre-commit", NULL))
+	if (!no_verify && run_commit_hook(use_editor, index_file, "pre-commit",
+					  amend ? "amend" : "noamend", NULL))
 		return 0;
 
 	if (squash_message) {
diff --git a/t/t7503-pre-commit-hook.sh b/t/t7503-pre-commit-hook.sh
index 99ed967..b400afe 100755
--- a/t/t7503-pre-commit-hook.sh
+++ b/t/t7503-pre-commit-hook.sh
@@ -133,4 +133,15 @@ test_expect_success 'check the author in hook' '
 	git show -s
 '
 
+# a hook that checks if "amend" is passed as an argument
+write_script "$HOOK" <<EOF
+test "\$1" = amend
+EOF
+
+test_expect_success 'check that "amend" argument is given' '
+       git commit --amend --allow-empty
+'
+
+test_must_fail git commit --allow-empty
+
 test_done

-- 
2.2.0.rc3