Before, when we had the following graph,
A---B---C (master)
\
D (side)
running 'git rebase --onto master... master side' would result in D
being always rebased, no matter what. However, the desired behavior is
that rebase should notice that this is fast-forwardable and do that
instead.
Add detection to `can_fast_forward` so that this case can be detected
and a fast-forward will be performed.
While we're at it, remove a trailing whitespace.
Signed-off-by: Denton Liu <liu.denton@xxxxxxxxx>
---
builtin/rebase.c | 40 +++++++++++++++++++++++-----------
t/t3400-rebase.sh | 2 +-
t/t3404-rebase-interactive.sh | 2 +-
t/t3432-rebase-fast-forward.sh | 2 +-
4 files changed, 30 insertions(+), 16 deletions(-)
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 77deebc65c..7aa6a090d4 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -895,12 +895,12 @@ 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;
- int res;
+ struct commit_list *merge_bases = NULL;
+ int res = 0;
if (!head)
return 0;
@@ -908,12 +908,29 @@ static int can_fast_forward(struct commit *onto, struct object_id *head_oid,
merge_bases = get_merge_bases(onto, head);
if (merge_bases && !merge_bases->next) {
oidcpy(merge_base, &merge_bases->item->object.oid);
- res = oideq(merge_base, &onto->object.oid);
+ if (!oideq(merge_base, &onto->object.oid))
+ goto done;
} else {
oidcpy(merge_base, &null_oid);
- res = 0;
+ goto done;
}
+
+ if (!upstream)
+ goto done;
+
free_commit_list(merge_bases);
+ merge_bases = get_merge_bases(upstream, head);
+ if (merge_bases && !merge_bases->next) {
+ if (!oideq(&onto->object.oid, &merge_bases->item->object.oid))
+ goto done;
+ } else
+ goto done;
+
+ res = 1;
+
+done:
+ if (merge_bases)
+ free_commit_list(merge_bases);
return res && is_linear_history(onto, head);
}
@@ -1682,13 +1699,10 @@ 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.
+ * but this should be done if this is not 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)) {
@@ -1782,7 +1796,7 @@ 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"));
diff --git a/t/t3400-rebase.sh b/t/t3400-rebase.sh
index 460d0523be..604d624ff8 100755
--- a/t/t3400-rebase.sh
+++ b/t/t3400-rebase.sh
@@ -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
)
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index b60b11f9f2..f054186cc7 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -1066,7 +1066,7 @@ 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
'
diff --git a/t/t3432-rebase-fast-forward.sh b/t/t3432-rebase-fast-forward.sh
index 3e6362dd9c..414b4216d6 100755
--- a/t/t3432-rebase-fast-forward.sh
+++ b/t/t3432-rebase-fast-forward.sh
@@ -54,6 +54,6 @@ test_expect_success 'add work to upstream' '
changes='our and their changes'
test_rebase_same_head success '--onto B B'
test_rebase_same_head success '--onto B... B'
-test_rebase_same_head failure '--onto master... master'
+test_rebase_same_head success '--onto master... master'
test_done
--
2.21.0.695.gaf8658f249
