[PATCH 07/15] ref_remove_duplicates(): simplify function

[Michael Haggerty <mhagger@alum.mit.edu>]

* Use a dedicated variable, ref, for referring to the current item
  rather than using the ref_map pointer for this purpose.

* Use a (struct ref **) as iteration variable to avoid having to keep
  track of prev and next in addition to the pointer to the current
  item.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 remote.c | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/remote.c b/remote.c
index a44e897..5ade07f 100644
--- a/remote.c
+++ b/remote.c
@@ -748,29 +748,33 @@ int for_each_remote(each_remote_fn fn, void *priv)
 void ref_remove_duplicates(struct ref *ref_map)
 {
 	struct string_list refs = STRING_LIST_INIT_NODUP;
-	struct string_list_item *item = NULL;
-	struct ref *prev = NULL, *next = NULL;
+	struct ref **p;
 
-	for (; ref_map; prev = ref_map, ref_map = next) {
-		next = ref_map->next;
-		if (!ref_map->peer_ref)
+	for (p = &ref_map; *p; ) {
+		struct ref *ref = *p;
+		struct string_list_item *item;
+
+		if (!ref->peer_ref) {
+			p = &ref->next;
 			continue;
+		}
 
-		item = string_list_insert(&refs, ref_map->peer_ref->name);
+		item = string_list_insert(&refs, ref->peer_ref->name);
 		if (item->util) {
 			/* Entry already existed */
 			if (strcmp(((struct ref *)item->util)->name,
-				   ref_map->name))
+				   ref->name))
 				die("%s tracks both %s and %s",
-				    ref_map->peer_ref->name,
+				    ref->peer_ref->name,
 				    ((struct ref *)item->util)->name,
-				    ref_map->name);
-			prev->next = ref_map->next;
-			free(ref_map->peer_ref);
-			free(ref_map);
-			ref_map = prev; /* skip this; we freed it */
+				    ref->name);
+			/* item is a duplicate; remove and free it */
+			*p = ref->next;
+			free(ref->peer_ref);
+			free(ref);
 		} else {
-			item->util = ref_map;
+			item->util = ref;
+			p = &ref->next;
 		}
 	}
 	string_list_clear(&refs, 0);
-- 
1.8.4