remote: die if branch is not found in repository

In a subsequent commit, we would like external-facing functions to be
able to accept "struct repository" and "struct branch" as a pair. This
is useful for functions like pushremote_for_branch(), which need to take
values from the remote_state and branch, even if branch == NULL.
However, a caller may supply an unrelated repository and branch, which
is not supported behavior.

To prevent misuse, add a die_on_missing_branch() helper function that
dies if a given branch is not from a given repository. Speed up the
existence check by replacing the branches list with a branches_hash
hashmap.

Like read_config(), die_on_missing_branch() is only called from
non-static functions; static functions are less prone to misuse because
they have strong conventions for keeping remote_state and branch in
sync.

Signed-off-by: Glen Choo <chooglen@google.com>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/remote.h b/remote.h
index 85a730b8ef..4a1209ae2c 100644
--- a/remote.h
+++ b/remote.h
@@ -43,9 +43,7 @@ struct remote_state {
 	int remotes_nr;
 	struct hashmap remotes_hash;
 
-	struct branch **branches;
-	int branches_alloc;
-	int branches_nr;
+	struct hashmap branches_hash;
 
 	struct branch *current_branch;
 	const char *pushremote_name;
@@ -292,6 +290,7 @@ int remote_find_tracking(struct remote *remote, struct refspec_item *refspec);
  * branch_get(name) for "refs/heads/{name}", or with branch_get(NULL) for HEAD.
  */
 struct branch {
+	struct hashmap_entry ent;
 
 	/* The short name of the branch. */
 	const char *name;