diff mbox series

[14/14] replay: stop assuming replayed branches do not diverge

Message ID 20230407072415.1360068-15-christian.couder@gmail.com (mailing list archive)
State New, archived
Headers show
Series Introduce new `git replay` command | expand

Commit Message

Christian Couder April 7, 2023, 7:24 a.m. UTC 
From: Elijah Newren <newren@gmail.com>

The replay command is able to replay multiple branches but when some of
them are based on other replayed branches, their commit should be
replayed onto already replayed commits.

For this purpose, let's store the replayed commit and its original
commit in a key value store, so that we can easily find and reused a
replayed commit instead of the original one.

Co-authored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 builtin/replay.c         | 44 ++++++++++++++++++++++++++--------
 t/t3650-replay-basics.sh | 52 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 10 deletions(-)
diff mbox series

Patch

diff --git a/builtin/replay.c b/builtin/replay.c
index 63b3ad518e..71815d5ca3 100644
--- a/builtin/replay.c
+++ b/builtin/replay.c
@@ -216,20 +216,33 @@  static void determine_replay_mode(struct rev_cmdline_info *cmd_info,
 	strset_clear(&rinfo.positive_refs);
 }
 
+static struct commit *mapped_commit(kh_oid_map_t *replayed_commits,
+				    struct commit *commit,
+				    struct commit *fallback)
+{
+	khint_t pos = kh_get_oid_map(replayed_commits, commit->object.oid);
+	if (pos == kh_end(replayed_commits))
+		return fallback;
+	return kh_value(replayed_commits, pos);
+}
+
 static struct commit *pick_regular_commit(struct commit *pickme,
-					  struct commit *last_commit,
+					  kh_oid_map_t *replayed_commits,
+					  struct commit *onto,
 					  struct merge_options *merge_opt,
 					  struct merge_result *result)
 {
-	struct commit *base;
+	struct commit *base, *replayed_base;
 	struct tree *pickme_tree, *base_tree;
 
 	base = pickme->parents->item;
+	replayed_base = mapped_commit(replayed_commits, base, onto);
 
+	result->tree = get_commit_tree(replayed_base);
 	pickme_tree = get_commit_tree(pickme);
 	base_tree = get_commit_tree(base);
 
-	merge_opt->branch1 = short_commit_name(last_commit);
+	merge_opt->branch1 = short_commit_name(replayed_base);
 	merge_opt->branch2 = short_commit_name(pickme);
 	merge_opt->ancestor = xstrfmt("parent of %s", merge_opt->branch2);
 
@@ -243,7 +256,7 @@  static struct commit *pick_regular_commit(struct commit *pickme,
 	merge_opt->ancestor = NULL;
 	if (!result->clean)
 		return NULL;
-	return create_commit(result->tree, pickme, last_commit);
+	return create_commit(result->tree, pickme, replayed_base);
 }
 
 int cmd_replay(int argc, const char **argv, const char *prefix)
@@ -259,6 +272,7 @@  int cmd_replay(int argc, const char **argv, const char *prefix)
 	struct merge_options merge_opt;
 	struct merge_result result;
 	struct strset *update_refs = NULL;
+	kh_oid_map_t *replayed_commits;
 	int ret = 0;
 
 	const char * const replay_usage[] = {
@@ -312,18 +326,20 @@  int cmd_replay(int argc, const char **argv, const char *prefix)
 	init_merge_options(&merge_opt, the_repository);
 	memset(&result, 0, sizeof(result));
 	merge_opt.show_rename_progress = 0;
-
-	result.tree = get_commit_tree(onto);
 	last_commit = onto;
+	replayed_commits = kh_init_oid_map();
 	while ((commit = get_revision(&revs))) {
 		const struct name_decoration *decoration;
+		khint_t pos;
+		int hr;
 
 		if (!commit->parents)
 			die(_("replaying down to root commit is not supported yet!"));
 		if (commit->parents->next)
 			die(_("replaying merge commits is not supported yet!"));
 
-		last_commit = pick_regular_commit(commit, last_commit, &merge_opt, &result);
+		last_commit = pick_regular_commit(commit, replayed_commits, onto,
+						  &merge_opt, &result);
 
 		if (!last_commit) {
 			/* TODO: handle conflicts in sparse worktree instead */
@@ -350,6 +366,13 @@  int cmd_replay(int argc, const char **argv, const char *prefix)
 			    oid_to_hex(&commit->object.oid));
 		}
 
+		/* Record commit -> last_commit mapping */
+		pos = kh_put_oid_map(replayed_commits, commit->object.oid, &hr);
+		if (hr == 0)
+			BUG("Duplicate rewritten commit: %s\n",
+			    oid_to_hex(&commit->object.oid));
+		kh_value(replayed_commits, pos) = last_commit;
+
 		/* Update any necessary branches */
 		if (advance_name)
 			continue;
@@ -379,13 +402,14 @@  int cmd_replay(int argc, const char **argv, const char *prefix)
 
 	/* Cleanup */
 	merge_finalize(&merge_opt, &result);
-	ret = result.clean;
-
-cleanup:
+	kh_destroy_oid_map(replayed_commits);
 	if (update_refs) {
 		strset_clear(update_refs);
 		free(update_refs);
 	}
+	ret = result.clean;
+
+cleanup:
 	release_revisions(&revs);
 
 	/* Return */
diff --git a/t/t3650-replay-basics.sh b/t/t3650-replay-basics.sh
index 976032ad18..b13bb7502c 100755
--- a/t/t3650-replay-basics.sh
+++ b/t/t3650-replay-basics.sh
@@ -105,4 +105,56 @@  test_expect_success 'using replay to also rebase a contained branch' '
 	test_cmp expect result
 '
 
+test_expect_success 'using replay to rebase multiple divergent branches' '
+	git replay --onto main ^topic1 topic2 topic4 >result &&
+
+	test_line_count = 2 result &&
+	cut -f 3 -d " " result >new-branch-tips &&
+
+	git log --format=%s $(head -n 1 new-branch-tips) >actual &&
+	test_write_lines E D M L B A >expect &&
+	test_cmp expect actual &&
+
+	git log --format=%s $(tail -n 1 new-branch-tips) >actual &&
+	test_write_lines J I M L B A >expect &&
+	test_cmp expect actual &&
+
+	printf "update refs/heads/topic2 " >expect &&
+	printf "%s " $(head -n 1 new-branch-tips) >>expect &&
+	git rev-parse topic2 >>expect &&
+	printf "update refs/heads/topic4 " >>expect &&
+	printf "%s " $(tail -n 1 new-branch-tips) >>expect &&
+	git rev-parse topic4 >>expect &&
+
+	test_cmp expect result
+'
+
+test_expect_success 'using replay to rebase multiple divergent branches, including contained ones' '
+	git replay --contained --onto main ^main topic2 topic3 topic4 >result &&
+
+	test_line_count = 4 result &&
+	cut -f 3 -d " " result >new-branch-tips &&
+
+	>expect &&
+	for i in 2 1 3 4
+	do
+		printf "update refs/heads/topic$i " >>expect &&
+		printf "%s " $(grep topic$i result | cut -f 3 -d " ") >>expect &&
+		git rev-parse topic$i >>expect || return 1
+	done &&
+
+	test_cmp expect result &&
+
+	test_write_lines F C M L B A >expect1 &&
+	test_write_lines E D C M L B A >expect2 &&
+	test_write_lines H G F C M L B A >expect3 &&
+	test_write_lines J I M L B A >expect4 &&
+
+	for i in 1 2 3 4
+	do
+		git log --format=%s $(grep topic$i result | cut -f 3 -d " ") >actual &&
+		test_cmp expect$i actual || return 1
+	done
+'
+
 test_done