[RFC PATCH 6/7] fetch: only populate existing_refs if needed

[Jonathan Tan <jonathantanmy@google.com>]

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 builtin/fetch.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/builtin/fetch.c b/builtin/fetch.c
index 29db219c68..6460ce3f4e 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -449,6 +449,7 @@ static struct ref *get_ref_map(struct remote *remote,
 	struct ref *orefs = NULL, **oref_tail = &orefs;
 
 	struct hashmap existing_refs;
+	int existing_refs_populated = 0;
 
 	if (rs->nr) {
 		struct refspec *fetch_refspec;
@@ -542,15 +543,18 @@ static struct ref *get_ref_map(struct remote *remote,
 
 	ref_map = ref_remove_duplicates(ref_map);
 
-	refname_hash_init(&existing_refs);
-	for_each_ref(add_one_refname, &existing_refs);
-
 	for (rm = ref_map; rm; rm = rm->next) {
 		if (rm->peer_ref) {
 			const char *refname = rm->peer_ref->name;
 			struct refname_hash_entry *peer_item;
 			unsigned int hash = strhash(refname);
 
+			if (!existing_refs_populated) {
+				refname_hash_init(&existing_refs);
+				for_each_ref(add_one_refname, &existing_refs);
+				existing_refs_populated = 1;
+			}
+
 			peer_item = hashmap_get_entry_from_hash(&existing_refs,
 						hash, refname,
 						struct refname_hash_entry, ent);
@@ -560,7 +564,8 @@ static struct ref *get_ref_map(struct remote *remote,
 			}
 		}
 	}
-	hashmap_free_entries(&existing_refs, struct refname_hash_entry, ent);
+	if (existing_refs_populated)
+		hashmap_free_entries(&existing_refs, struct refname_hash_entry, ent);
 
 	return ref_map;
 }
-- 
2.28.0.163.g6104cc2f0b6-goog