rebase -i: invoke post-rewrite hook

Aside from the same issue that rebase also has (remembering the
original commit across a conflict resolution), rebase -i brings an
extra twist: We need to defer writing the rewritten list in the case
of {squash,fixup} because their rewritten result should be the last
commit in the squashed group.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-rebase--interactive.sh

@@ -96,6 +96,13 @@ AUTHOR_SCRIPT="$DOTEST"/author-script
 # command is processed, this file is deleted.
 AMEND="$DOTEST"/amend
 
+# For the post-rewrite hook, we make a list of rewritten commits and
+# their new sha1s.  The rewritten-pending list keeps the sha1s of
+# commits that have been processed, but not committed yet,
+# e.g. because they are waiting for a 'squash' command.
+REWRITTEN_LIST="$DOTEST"/rewritten-list
+REWRITTEN_PENDING="$DOTEST"/rewritten-pending
+
 PRESERVE_MERGES=
 STRATEGY=
 ONTO=
@@ -198,6 +205,7 @@ make_patch () {
 }
 
 die_with_patch () {
+	echo "$1" > "$DOTEST"/stopped-sha
 	make_patch "$1"
 	git rerere
 	die "$2"
@@ -348,6 +356,7 @@ pick_one_preserving_merges () {
 				printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
 				die_with_patch $sha1 "Error redoing merge $sha1"
 			fi
+			echo "$sha1 $(git rev-parse HEAD^0)" >> "$REWRITTEN_LIST"
 			;;
 		*)
 			output git cherry-pick "$@" ||
@@ -425,6 +434,26 @@ die_failed_squash() {
 	die_with_patch $1 ""
 }
 
+flush_rewritten_pending() {
+	test -s "$REWRITTEN_PENDING" || return
+	newsha1="$(git rev-parse HEAD^0)"
+	sed "s/$/ $newsha1/" < "$REWRITTEN_PENDING" >> "$REWRITTEN_LIST"
+	rm -f "$REWRITTEN_PENDING"
+}
+
+record_in_rewritten() {
+	oldsha1="$(git rev-parse $1)"
+	echo "$oldsha1" >> "$REWRITTEN_PENDING"
+
+	case "$(peek_next_command)" in
+	    squash|s|fixup|f)
+		;;
+	    *)
+		flush_rewritten_pending
+		;;
+	esac
+}
+
 do_next () {
 	rm -f "$MSG" "$AUTHOR_SCRIPT" "$AMEND" || exit
 	read command sha1 rest < "$TODO"
@@ -438,6 +467,7 @@ do_next () {
 		mark_action_done
 		pick_one $sha1 ||
 			die_with_patch $sha1 "Could not apply $sha1... $rest"
+		record_in_rewritten $sha1
 		;;
 	reword|r)
 		comment_for_reflog reword
@@ -446,6 +476,7 @@ do_next () {
 		pick_one $sha1 ||
 			die_with_patch $sha1 "Could not apply $sha1... $rest"
 		git commit --amend --no-post-rewrite
+		record_in_rewritten $sha1
 		;;
 	edit|e)
 		comment_for_reflog edit
@@ -453,6 +484,7 @@ do_next () {
 		mark_action_done
 		pick_one $sha1 ||
 			die_with_patch $sha1 "Could not apply $sha1... $rest"
+		echo "$1" > "$DOTEST"/stopped-sha
 		make_patch $sha1
 		git rev-parse --verify HEAD > "$AMEND"
 		warn "Stopped at $sha1... $rest"
@@ -509,6 +541,7 @@ do_next () {
 			rm -f "$SQUASH_MSG" "$FIXUP_MSG"
 			;;
 		esac
+		record_in_rewritten $sha1
 		;;
 	*)
 		warn "Unknown command: $command $sha1 $rest"
@@ -537,6 +570,11 @@ do_next () {
 		test ! -f "$DOTEST"/verbose ||
 			git diff-tree --stat $(cat "$DOTEST"/head)..HEAD
 	} &&
+	if test -x "$GIT_DIR"/hooks/post-rewrite &&
+		test -s "$REWRITTEN_LIST"; then
+		"$GIT_DIR"/hooks/post-rewrite rebase < "$REWRITTEN_LIST"
+		true # we don't care if this hook failed
+	fi &&
 	rm -rf "$DOTEST" &&
 	git gc --auto &&
 	warn "Successfully rebased and updated $HEADNAME."
@@ -571,7 +609,12 @@ skip_unnecessary_picks () {
 		esac
 		echo "$command${sha1:+ }$sha1${rest:+ }$rest" >&$fd
 	done <"$TODO" >"$TODO.new" 3>>"$DONE" &&
-	mv -f "$TODO".new "$TODO" ||
+	mv -f "$TODO".new "$TODO" &&
+	case "$(peek_next_command)" in
+	squash|s|fixup|f)
+		record_in_rewritten "$ONTO"
+		;;
+	esac ||
 	die "Could not skip unnecessary pick commands"
 }
 
@@ -685,6 +728,7 @@ first and then run 'git rebase --continue' again."
 				test -n "$amend" && git reset --soft $amend
 				die "Could not commit staged changes."
 			}
+			record_in_rewritten "$(cat "$DOTEST"/stopped-sha)"
 		fi
 
 		require_clean_work_tree

t/t5407-post-rewrite-hook.sh

@@ -79,4 +79,105 @@ EOF
 	verify_hook_input
 '
 
+test_expect_success 'git rebase -m' '
+	git reset --hard D &&
+	clear_hook_input &&
+	test_must_fail git rebase -m --onto A B &&
+	echo C > foo &&
+	git add foo &&
+	git rebase --continue &&
+	echo rebase >expected.args &&
+	cat >expected.data <<EOF &&
+$(git rev-parse C) $(git rev-parse HEAD^)
+$(git rev-parse D) $(git rev-parse HEAD)
+EOF
+	verify_hook_input
+'
+
+test_expect_success 'git rebase -m --skip' '
+	git reset --hard D &&
+	clear_hook_input &&
+	test_must_fail git rebase --onto A B &&
+	test_must_fail git rebase --skip &&
+	echo D > foo &&
+	git add foo &&
+	git rebase --continue &&
+	echo rebase >expected.args &&
+	cat >expected.data <<EOF &&
+$(git rev-parse D) $(git rev-parse HEAD)
+EOF
+	verify_hook_input
+'
+
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
+set_fake_editor
+
+# Helper to work around the lack of one-shot exporting for
+# test_must_fail (as it is a shell function)
+test_fail_interactive_rebase () {
+	(
+		FAKE_LINES="$1" &&
+		shift &&
+		export FAKE_LINES &&
+		test_must_fail git rebase -i "$@"
+	)
+}
+
+test_expect_success 'git rebase -i (unchanged)' '
+	git reset --hard D &&
+	clear_hook_input &&
+	test_fail_interactive_rebase "1 2" --onto A B &&
+	echo C > foo &&
+	git add foo &&
+	git rebase --continue &&
+	echo rebase >expected.args &&
+	cat >expected.data <<EOF &&
+$(git rev-parse C) $(git rev-parse HEAD^)
+$(git rev-parse D) $(git rev-parse HEAD)
+EOF
+	verify_hook_input
+'
+
+test_expect_success 'git rebase -i (skip)' '
+	git reset --hard D &&
+	clear_hook_input &&
+	test_fail_interactive_rebase "2" --onto A B &&
+	echo D > foo &&
+	git add foo &&
+	git rebase --continue &&
+	echo rebase >expected.args &&
+	cat >expected.data <<EOF &&
+$(git rev-parse D) $(git rev-parse HEAD)
+EOF
+	verify_hook_input
+'
+
+test_expect_success 'git rebase -i (squash)' '
+	git reset --hard D &&
+	clear_hook_input &&
+	test_fail_interactive_rebase "1 squash 2" --onto A B &&
+	echo C > foo &&
+	git add foo &&
+	git rebase --continue &&
+	echo rebase >expected.args &&
+	cat >expected.data <<EOF &&
+$(git rev-parse C) $(git rev-parse HEAD)
+$(git rev-parse D) $(git rev-parse HEAD)
+EOF
+	verify_hook_input
+'
+
+test_expect_success 'git rebase -i (fixup without conflict)' '
+	git reset --hard D &&
+	clear_hook_input &&
+	FAKE_LINES="1 fixup 2" git rebase -i B &&
+	echo rebase >expected.args &&
+	cat >expected.data <<EOF &&
+$(git rev-parse C) $(git rev-parse HEAD)
+$(git rev-parse D) $(git rev-parse HEAD)
+EOF
+	verify_hook_input
+'
+
 test_done