@@ -223,20 +223,33 @@ 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 = repo_get_commit_tree(the_repository, replayed_base);
 	pickme_tree = repo_get_commit_tree(the_repository, pickme);
 	base_tree = repo_get_commit_tree(the_repository, 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);
 

@@ -250,7 +263,7 @@ 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)

@@ -266,6 +279,7 @@ 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, i;
 
 	const char * const replay_usage[] = {

@@ -348,21 +362,30 @@ 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 = repo_get_commit_tree(the_repository, 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)
 			break;
 
+		/* 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;

@@ -391,13 +414,14 @@ int cmd_replay(int argc, const char **argv, const char *prefix)
 	}
 
 	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 */

@@ -159,4 +159,56 @@ test_expect_success 'using replay on bare repo to also rebase a contained branch
 	test_cmp expect result-bare
 '
 
+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 " $(tail -n 1 new-branch-tips) >>expect &&
+	git rev-parse topic4 >>expect &&
+
+	test_cmp expect result
+'
+
+test_expect_success 'using replay on bare repo to rebase multiple divergent branches, including contained ones' '
+	git -C bare replay --contained --onto main ^main topic2 topic3 topic4 >result &&
+
+	test_line_count = 4 result &&
+	cut -f 3 -d " " result >new-branch-tips &&
+
+	>expect &&
+	for i in 2 1 3 4
+	do
+		printf "update refs/heads/topic$i " >>expect &&
+		printf "%s " $(grep topic$i result | cut -f 3 -d " ") >>expect &&
+		git -C bare 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 -C bare log --format=%s $(grep topic$i result | cut -f 3 -d " ") >actual &&
+		test_cmp expect$i actual || return 1
+	done
+'
+
 test_done