commit -c/-C/--amend: reset timestamp and authorship to committer with --reset-author

When we use -c, -C, or --amend, we are trying one of two things: using the
source as a template or modifying a commit with corrections.

When these options are used, the authorship and timestamp recorded in the
newly created commit are always taken from the original commit.  This is
inconvenient when we just want to borrow the commit log message or when
our change to the code is so significant that we should take over the
authorship (with the blame for bugs we introduce, of course).

The new --reset-author option is meant to solve this need by regenerating
the timestamp and setting the committer as the new author.

Signed-off-by: Erick Mattos <erick.mattos@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 114 insertions, 0 deletions

diff --git a/t/t7509-commit.sh b/t/t7509-commit.sh
new file mode 100755
index 0000000..d52c060
--- /dev/null
+++ b/t/t7509-commit.sh
@@ -0,0 +1,114 @@
+#!/bin/sh
+#
+# Copyright (c) 2009 Erick Mattos
+#
+
+test_description='git commit --reset-author'
+
+. ./test-lib.sh
+
+author_header () {
+	git cat-file commit "$1" |
+	sed -n -e '/^$/q' -e '/^author /p'
+}
+
+message_body () {
+	git cat-file commit "$1" |
+	sed -e '1,/^$/d'
+}
+
+test_expect_success '-C option copies authorship and message' '
+	echo "Initial" >foo &&
+	git add foo &&
+	test_tick &&
+	git commit -m "Initial Commit" --author Frigate\ \<flying@over.world\> &&
+	git tag Initial &&
+	echo "Test 1" >>foo &&
+	test_tick &&
+	git commit -a -C Initial &&
+	author_header Initial >expect &&
+	author_header HEAD >actual &&
+	test_cmp expect actual &&
+
+	message_body Initial >expect &&
+	message_body HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '-C option copies only the message with --reset-author' '
+	echo "Test 2" >>foo &&
+	test_tick &&
+	git commit -a -C Initial --reset-author &&
+	echo "author $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> $GIT_AUTHOR_DATE" >expect &&
+	author_header HEAD >actual
+	test_cmp expect actual &&
+
+	message_body Initial >expect &&
+	message_body HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '-c option copies authorship and message' '
+	echo "Test 3" >>foo &&
+	test_tick &&
+	EDITOR=: VISUAL=: git commit -a -c Initial &&
+	author_header Initial >expect &&
+	author_header HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '-c option copies only the message with --reset-author' '
+	echo "Test 4" >>foo &&
+	test_tick &&
+	EDITOR=: VISUAL=: git commit -a -c Initial --reset-author &&
+	echo "author $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> $GIT_AUTHOR_DATE" >expect &&
+	author_header HEAD >actual &&
+	test_cmp expect actual &&
+
+	message_body Initial >expect &&
+	message_body HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--amend option copies authorship' '
+	git checkout Initial &&
+	echo "Test 5" >>foo &&
+	test_tick &&
+	git commit -a --amend -m "amend test" &&
+	author_header Initial >expect &&
+	author_header HEAD >actual &&
+
+	echo "amend test" >expect &&
+	message_body HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--reset-author makes the commit ours even with --amend option' '
+	git checkout Initial &&
+	echo "Test 6" >>foo &&
+	test_tick &&
+	git commit -a --reset-author -m "Changed again" --amend &&
+	echo "author $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> $GIT_AUTHOR_DATE" >expect &&
+	author_header HEAD >actual &&
+	test_cmp expect actual &&
+
+	echo "Changed again" >expect &&
+	message_body HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--reset-author and --author are mutually exclusive' '
+	git checkout Initial &&
+	echo "Test 7" >>foo &&
+	test_tick &&
+	test_must_fail git commit -a --reset-author --author="Xyzzy <frotz@nitfol.xz>"
+'
+
+test_expect_success '--reset-author should be rejected without -c/-C/--amend' '
+	git checkout Initial &&
+	echo "Test 7" >>foo &&
+	test_tick &&
+	test_must_fail git commit -a --reset-author -m done
+'
+
+test_done