rebase -m: remember allow_rerere_autoupdate option

If '--[no-]allow_rerere_autoupdate' is passed when 'git rebase -m' is
called and a merge conflict occurs, the flag will be forgotten for the
rest of the rebase process. Make rebase remember it by saving the
value.

Signed-off-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-rebase.sh

@@ -84,6 +84,8 @@ read_basic_state () {
 	test -f "$state_dir"/strategy && strategy="$(cat "$state_dir"/strategy)"
 	test -f "$state_dir"/strategy_opts &&
 		strategy_opts="$(cat "$state_dir"/strategy_opts)"
+	test -f "$state_dir"/allow_rerere_autoupdate &&
+		allow_rerere_autoupdate="$(cat "$state_dir"/allow_rerere_autoupdate)"
 }
 
 write_basic_state () {
@@ -95,6 +97,8 @@ write_basic_state () {
 	test -n "$strategy" && echo "$strategy" > "$state_dir"/strategy
 	test -n "$strategy_opts" && echo "$strategy_opts" > \
 		"$state_dir"/strategy_opts
+	test -n "$allow_rerere_autoupdate" && echo "$allow_rerere_autoupdate" > \
+		"$state_dir"/allow_rerere_autoupdate
 }
 
 output () {

t/t3418-rebase-continue.sh

@@ -74,4 +74,25 @@ test_expect_success 'rebase --continue remembers merge strategy and options' '
 	test -f funny.was.run
 '
 
+test_expect_success 'rebase --continue remembers --rerere-autoupdate' '
+	rm -fr .git/rebase-* &&
+	git reset --hard commit-new-file-F3-on-topic-branch &&
+	git checkout master
+	test_commit "commit-new-file-F3" F3 3 &&
+	git config rerere.enabled true &&
+	test_must_fail git rebase -m master topic &&
+	echo "Resolved" >F2 &&
+	git add F2 &&
+	test_must_fail git rebase --continue &&
+	echo "Resolved" >F3 &&
+	git add F3 &&
+	git rebase --continue &&
+	git reset --hard topic@{1} &&
+	test_must_fail git rebase -m --rerere-autoupdate master &&
+	test "$(cat F2)" = "Resolved" &&
+	test_must_fail git rebase --continue &&
+	test "$(cat F3)" = "Resolved" &&
+	git rebase --continue
+'
+
 test_done