remote: let guess_remote_head() optionally return all matches

Determining HEAD is ambiguous since it is done by comparing SHA1s.

In the case of multiple matches we return refs/heads/master if it
matches, else we return the first match we encounter. builtin-remote
needs all matches returned to it, so add a flag for it to request such.

To be simple and consistent, the return value is now a copy (including
peer_ref) of the matching refs.

Originally contributed by Jeff King along with the prior commit as a
single patch.

Signed-off-by: Jay Soffian <jaysoffian@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/remote.h b/remote.h
index db49ce0467..de3d21b662 100644
--- a/remote.h
+++ b/remote.h
@@ -139,12 +139,14 @@ int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs);
 int format_tracking_info(struct branch *branch, struct strbuf *sb);
 
 struct ref *get_local_heads(void);
-
 /*
- * Look for a ref in refs whose SHA1 matches head, first checking if
- * refs/heads/master matches. Return NULL if nothing matches or if head
- * is NULL.
+ * Find refs from a list which are likely to be pointed to by the given HEAD
+ * ref. If 'all' is false, returns the most likely ref; otherwise, returns a
+ * list of all candidate refs. If no match is found (or 'head' is NULL),
+ * returns NULL. All returns are newly allocated and should be freed.
  */
-const struct ref *guess_remote_head(const struct ref *head,
-				    const struct ref *refs);
+struct ref *guess_remote_head(const struct ref *head,
+			      const struct ref *refs,
+			      int all);
+
 #endif