diff --git a/builtin/pull.c b/builtin/pull.c index bf3fd3f9c8..2a41d415b2 100644 --- a/builtin/pull.c +++ b/builtin/pull.c @@ -878,10 +878,24 @@ int cmd_pull(int argc, const char **argv, const char *prefix) if (merge_heads.nr > 1) die(_("Cannot merge multiple branches into empty head.")); return pull_into_void(*merge_heads.sha1, curr_head); - } else if (opt_rebase) { - if (merge_heads.nr > 1) - die(_("Cannot rebase onto multiple branches.")); + } + if (opt_rebase && merge_heads.nr > 1) + die(_("Cannot rebase onto multiple branches.")); + + if (opt_rebase) { + struct commit_list *list = NULL; + struct commit *merge_head, *head; + + head = lookup_commit_reference(orig_head); + commit_list_insert(head, &list); + merge_head = lookup_commit_reference(merge_heads.sha1[0]); + if (is_descendant_of(merge_head, list)) { + /* we can fast-forward this without invoking rebase */ + opt_ff = "--ff-only"; + return run_merge(); + } return run_rebase(curr_head, *merge_heads.sha1, rebase_fork_point); - } else + } else { return run_merge(); + } } diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh index a0013ee32f..7887b6d97b 100755 --- a/t/t5520-pull.sh +++ b/t/t5520-pull.sh @@ -237,6 +237,23 @@ test_expect_success '--rebase' ' test new = "$(git show HEAD:file2)" ' +test_expect_success '--rebase fast forward' ' + git reset --hard before-rebase && + git checkout -b ff && + echo another modification >file && + git commit -m third file && + + git checkout to-rebase && + git pull --rebase . ff && + test "$(git rev-parse HEAD)" = "$(git rev-parse ff)" && + + # The above only validates the result. Did we actually bypass rebase? + git reflog -1 >reflog.actual && + sed "s/^[0-9a-f][0-9a-f]*/OBJID/" reflog.actual >reflog.fuzzy && + echo "OBJID HEAD@{0}: pull --rebase . ff: Fast-forward" >reflog.expected && + test_cmp reflog.expected reflog.fuzzy +' + test_expect_success '--rebase fails with multiple branches' ' git reset --hard before-rebase && test_must_fail git pull --rebase . copy master 2>err &&