@@ -878,8 +878,8 @@ static int is_linear_history(struct commit *from, struct commit *to)
return 1;
}
-static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
- struct object_id *merge_base)
+static int can_fast_forward(struct commit *onto, struct commit *upstream,
+ struct object_id *head_oid, struct object_id *merge_base)
{
struct commit *head = lookup_commit(the_repository, head_oid);
struct commit_list *merge_bases = NULL;
@@ -898,6 +898,17 @@ static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
if (!oideq(merge_base, &onto->object.oid))
goto done;
+ if (!upstream)
+ goto done;
+
+ free_commit_list(merge_bases);
+ merge_bases = get_merge_bases(upstream, head);
+ if (!merge_bases || merge_bases->next)
+ goto done;
+
+ if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
+ goto done;
+
res = 1;
done:
@@ -1664,13 +1675,13 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
/*
* Check if we are already based on onto with linear history,
- * but this should be done only when upstream and onto are the same
- * and if this is not an interactive rebase.
+ * in which case we could fast-forward without replacing the commits
+ * with new commits recreated by replaying their changes. This
+ * optimization must not be done if this is an interactive rebase.
*/
- if (can_fast_forward(options.onto, &options.orig_head, &merge_base) &&
- !is_interactive(&options) && !options.restrict_revision &&
- options.upstream &&
- !oidcmp(&options.upstream->object.oid, &options.onto->object.oid)) {
+ if (can_fast_forward(options.onto, options.upstream, &options.orig_head,
+ &merge_base) &&
+ !is_interactive(&options) && !options.restrict_revision) {
int flag;
if (!(options.flags & REBASE_FORCE)) {
@@ -1764,7 +1775,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
strbuf_addf(&msg, "%s: checkout %s",
getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
if (reset_head(&options.onto->object.oid, "checkout", NULL,
- RESET_HEAD_DETACH | RESET_ORIG_HEAD |
+ RESET_HEAD_DETACH | RESET_ORIG_HEAD |
RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
NULL, msg.buf))
die(_("Could not detach HEAD"));
@@ -295,7 +295,7 @@ test_expect_success 'rebase--am.sh and --show-current-patch' '
echo two >>init.t &&
git commit -a -m two &&
git tag two &&
- test_must_fail git rebase --onto init HEAD^ &&
+ test_must_fail git rebase -f --onto init HEAD^ &&
GIT_TRACE=1 git rebase --show-current-patch >/dev/null 2>stderr &&
grep "show.*$(git rev-parse two)" stderr
)
@@ -1063,7 +1063,7 @@ test_expect_success C_LOCALE_OUTPUT 'rebase --edit-todo does not work on non-int
git reset --hard &&
git checkout conflict-branch &&
set_fake_editor &&
- test_must_fail git rebase --onto HEAD~2 HEAD~ &&
+ test_must_fail git rebase -f --onto HEAD~2 HEAD~ &&
test_must_fail git rebase --edit-todo &&
git rebase --abort
'
@@ -106,9 +106,9 @@ test_expect_success 'add work same to upstream' '
changes='our and their changes'
test_rebase_same_head success noop same success noop-force diff --onto B B
test_rebase_same_head success noop same success noop-force diff --onto B... B
-test_rebase_same_head failure work same success work diff --onto master... master
+test_rebase_same_head success noop same success work diff --onto master... master
test_rebase_same_head failure work same success work diff --fork-point --onto B B
test_rebase_same_head failure work same success work diff --fork-point --onto B... B
-test_rebase_same_head failure work same success work diff --fork-point --onto master... master
+test_rebase_same_head success noop same success work diff --fork-point --onto master... master
test_done