rebase: better rearranging of fixup!/squash! lines with --autosquash

The current behvaior of --autosquash can duplicate fixup!/squash! lines
if they match multiple commits, and it can also apply them to commits
that come after them in the todo list. Even more oddly, a commit that
looks like "fixup! fixup!" will match itself and be duplicated in the
todo list.

Change the todo list rearranging to mark all commits as used as soon
as they are emitted, and to avoid emitting a fixup/squash commit if the
commit has already been marked as used.

Signed-off-by: Kevin Ballard <kevin@sb.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 47 insertions, 0 deletions

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index a27952d9f..379bbac5e 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -687,8 +687,12 @@ rearrange_squash () {
 		*" $sha1 "*) continue ;;
 		esac
 		printf '%s\n' "$pick $sha1 $message"
+		used="$used$sha1 "
 		while read -r squash action msg
 		do
+			case " $used" in
+			*" $squash "*) continue ;;
+			esac
 			case "$message" in
 			"$msg"*)
 				printf '%s\n' "$action $squash $action! $msg"
diff --git a/t/t3415-rebase-autosquash.sh b/t/t3415-rebase-autosquash.sh
index fd2184ce7..712bbe86b 100755
--- a/t/t3415-rebase-autosquash.sh
+++ b/t/t3415-rebase-autosquash.sh
@@ -94,4 +94,47 @@ test_expect_success 'misspelled auto squash' '
 	test 0 = $(git rev-list final-missquash...HEAD | wc -l)
 '
 
+test_expect_success 'auto squash that matches 2 commits' '
+	git reset --hard base &&
+	echo 4 >file4 &&
+	git add file4 &&
+	test_tick &&
+	git commit -m "first new commit" &&
+	echo 1 >file1 &&
+	git add -u &&
+	test_tick &&
+	git commit -m "squash! first" &&
+	git tag final-multisquash &&
+	test_tick &&
+	git rebase --autosquash -i HEAD~4 &&
+	git log --oneline >actual &&
+	test 4 = $(wc -l <actual) &&
+	git diff --exit-code final-multisquash &&
+	test 1 = "$(git cat-file blob HEAD^^:file1)" &&
+	test 2 = $(git cat-file commit HEAD^^ | grep first | wc -l) &&
+	test 1 = $(git cat-file commit HEAD | grep first | wc -l)
+'
+
+test_expect_success 'auto squash that matches a commit after the squash' '
+	git reset --hard base &&
+	echo 1 >file1 &&
+	git add -u &&
+	test_tick &&
+	git commit -m "squash! third" &&
+	echo 4 >file4 &&
+	git add file4 &&
+	test_tick &&
+	git commit -m "third commit" &&
+	git tag final-presquash &&
+	test_tick &&
+	git rebase --autosquash -i HEAD~4 &&
+	git log --oneline >actual &&
+	test 5 = $(wc -l <actual) &&
+	git diff --exit-code final-presquash &&
+	test 0 = "$(git cat-file blob HEAD^^:file1)" &&
+	test 1 = "$(git cat-file blob HEAD^:file1)" &&
+	test 1 = $(git cat-file commit HEAD | grep third | wc -l) &&
+	test 1 = $(git cat-file commit HEAD^ | grep third | wc -l)
+'
+
 test_done