remote: build up the list of refs to remove

When removing the remote-tracking branches, build up the list and remove
in two steps, working around an issue with the iterator. Removing while
we're iterating over the refs can cause us to miss references.

src/remote.c

@@ -1809,24 +1809,50 @@ static int remove_branch_config_related_entries(
 	return error;
 }
 
-static int remove_refs(git_repository *repo, const char *glob)
+static int remove_refs(git_repository *repo, const git_refspec *spec)
 {
-	git_reference_iterator *iter;
+	git_reference_iterator *iter = NULL;
+	git_vector refs;
 	const char *name;
+	char *dup;
 	int error;
+	size_t i;
 
-	if ((error = git_reference_iterator_glob_new(&iter, repo, glob)) < 0)
+	if ((error = git_vector_init(&refs, 8, NULL)) < 0)
 		return error;
 
+	if ((error = git_reference_iterator_new(&iter, repo)) < 0)
+		goto cleanup;
+
 	while ((error = git_reference_next_name(&name, iter)) == 0) {
-		if ((error = git_reference_remove(repo, name)) < 0)
-			break;
-	}
-	git_reference_iterator_free(iter);
+		if (!git_refspec_dst_matches(spec, name))
+			continue;
+
+		dup = git__strdup(name);
+		if (!dup) {
+			error = -1;
+			goto cleanup;
+		}
 
+		if ((error = git_vector_insert(&refs, dup)) < 0)
+			goto cleanup;
+	}
 	if (error == GIT_ITEROVER)
 		error = 0;
+	if (error < 0)
+		goto cleanup;
+
+	git_vector_foreach(&refs, i, name) {
+		if ((error = git_reference_remove(repo, name)) < 0)
+			break;
+	}
 
+cleanup:
+	git_reference_iterator_free(iter);
+	git_vector_foreach(&refs, i, dup) {
+		git__free(dup);
+	}
+	git_vector_free(&refs);
 	return error;
 }
 
@@ -1848,7 +1874,7 @@ static int remove_remote_tracking(git_repository *repo, const char *remote_name)
 		if (refspec == NULL)
 			continue;
 
-		if ((error = remove_refs(repo, git_refspec_dst(refspec))) < 0)
+		if ((error = remove_refs(repo, refspec)) < 0)
 			break;
 	}