rebase -i: handle fixup! fixup! in --autosquash

In rebase -i --autosquash, ignore all "fixup! " or "squash! " after the
first.  This supports the case when a git commit --fixup/--squash referred
to an earlier fixup/squash instead of the original commit (whether
intentionally, as when the user expressly meant to note that the commit
fixes an earlier fixup; or inadvertently, as when the user meant to refer to
the original commit with :/msg; or out of laziness, as when the user could
remember how to refer to the fixup but not the original).

In the todo list, the full commit message is preserved, in case it provides
useful cues to the user.  A test helper set_cat_todo_editor is introduced to
check this.

Helped-by: Thomas Rast <trast@inf.ethz.ch>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Andrew Pimlott <andrew@pimlott.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 71 insertions, 0 deletions

diff --git a/t/lib-rebase.sh b/t/lib-rebase.sh
index 4b74ae460b..cfd340943b 100644
--- a/t/lib-rebase.sh
+++ b/t/lib-rebase.sh
@@ -66,6 +66,20 @@ EOF
 	chmod a+x fake-editor.sh
 }
 
+# After set_cat_todo_editor, rebase -i will write the todo list (ignoring
+# blank lines and comments) to stdout, and exit failure (so you should run
+# it with test_must_fail).  This can be used to verify the expected user
+# experience, for todo list changes that do not affect the outcome of
+# rebase; or as an extra check in addition to checking the outcome.
+
+set_cat_todo_editor () {
+	write_script fake-editor.sh <<-\EOF
+	grep "^[^#]" "$1"
+	exit 1
+	EOF
+	test_set_editor "$(pwd)/fake-editor.sh"
+}
+
 # checks that the revisions in "$2" represent a linear range with the
 # subjects in "$1"
 test_linear_range () {
diff --git a/t/t3415-rebase-autosquash.sh b/t/t3415-rebase-autosquash.sh
index a1e86c4097..41370ab998 100755
--- a/t/t3415-rebase-autosquash.sh
+++ b/t/t3415-rebase-autosquash.sh
@@ -4,6 +4,8 @@ test_description='auto squash'
 
 . ./test-lib.sh
 
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
 test_expect_success setup '
 	echo 0 >file0 &&
 	git add . &&
@@ -193,4 +195,59 @@ test_expect_success 'use commit --squash' '
 	test_auto_commit_flags squash 2
 '
 
+test_auto_fixup_fixup () {
+	git reset --hard base &&
+	echo 1 >file1 &&
+	git add -u &&
+	test_tick &&
+	git commit -m "$1! first" &&
+	echo 2 >file1 &&
+	git add -u &&
+	test_tick &&
+	git commit -m "$1! $2! first" &&
+	git tag "final-$1-$2" &&
+	test_tick &&
+	(
+		set_cat_todo_editor &&
+		test_must_fail git rebase --autosquash -i HEAD^^^^ >actual &&
+		cat >expected <<-EOF &&
+		pick $(git rev-parse --short HEAD^^^) first commit
+		$1 $(git rev-parse --short HEAD^) $1! first
+		$1 $(git rev-parse --short HEAD) $1! $2! first
+		pick $(git rev-parse --short HEAD^^) second commit
+		EOF
+		test_cmp expected actual
+	) &&
+	git rebase --autosquash -i HEAD^^^^ &&
+	git log --oneline >actual &&
+	test_line_count = 3 actual
+	git diff --exit-code "final-$1-$2" &&
+	test 2 = "$(git cat-file blob HEAD^:file1)" &&
+	if test "$1" = "fixup"
+	then
+		test 1 = $(git cat-file commit HEAD^ | grep first | wc -l)
+	elif test "$1" = "squash"
+	then
+		test 3 = $(git cat-file commit HEAD^ | grep first | wc -l)
+	else
+		false
+	fi
+}
+
+test_expect_success 'fixup! fixup!' '
+	test_auto_fixup_fixup fixup fixup
+'
+
+test_expect_success 'fixup! squash!' '
+	test_auto_fixup_fixup fixup squash
+'
+
+test_expect_success 'squash! squash!' '
+	test_auto_fixup_fixup squash squash
+'
+
+test_expect_success 'squash! fixup!' '
+	test_auto_fixup_fixup squash fixup
+'
+
 test_done