pull: refactor fast-forward check

We would like to be able to make this check before the decision to
rebase is made in a future step.  Besides, using a separate helper
makes the code easier to follow.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/pull.c b/builtin/pull.c
index aa56ebcdd0dce08f61fcaa5d1762d4efb8876adc..03e6d53243ae6ef1e1bcd87301e49d1b6278248c 100644 (file)
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -924,6 +924,20 @@ static int run_rebase(const struct object_id *newbase,
        return ret;
 }
 
+static int get_can_ff(struct object_id *orig_head, struct object_id *orig_merge_head)
+{
+       int ret;
+       struct commit_list *list = NULL;
+       struct commit *merge_head, *head;
+
+       head = lookup_commit_reference(the_repository, orig_head);
+       commit_list_insert(head, &list);
+       merge_head = lookup_commit_reference(the_repository, orig_merge_head);
+       ret = repo_is_descendant_of(the_repository, merge_head, list);
+       free_commit_list(list);
+       return ret;
+}
+
 int cmd_pull(int argc, const char **argv, const char *prefix)
 {
        const char *repo, **refspecs;
@@ -1040,22 +1054,12 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
                    submodule_touches_in_range(the_repository, &upstream, &curr_head))
                        die(_("cannot rebase with locally recorded submodule modifications"));
                if (!autostash) {
-                       struct commit_list *list = NULL;
-                       struct commit *merge_head, *head;
-
-                       head = lookup_commit_reference(the_repository,
-                                                      &orig_head);
-                       commit_list_insert(head, &list);
-                       merge_head = lookup_commit_reference(the_repository,
-                                                            &merge_heads.oid[0]);
-                       if (repo_is_descendant_of(the_repository,
-                                                 merge_head, list)) {
+                       if (get_can_ff(&orig_head, &merge_heads.oid[0])) {
                                /* we can fast-forward this without invoking rebase */
                                opt_ff = "--ff-only";
                                ran_ff = 1;
                                ret = run_merge();
                        }
-                       free_commit_list(list);
                }
                if (!ran_ff)
                        ret = run_rebase(&newbase, &upstream);