object_array: factor out slopbuf-freeing logic

This is not a lot of code, but it's a logical construct that
should not need to be repeated (and we are about to add a
third repetition).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

object.c

@@ -355,6 +355,16 @@ void add_object_array_with_context(struct object *obj, const char *name, struct
 		add_object_array_with_mode_context(obj, name, array, S_IFINVALID, context);
 }
 
+/*
+ * Free all memory associated with an entry; the result is
+ * in an unspecified state and should not be examined.
+ */
+static void object_array_release_entry(struct object_array_entry *ent)
+{
+	if (ent->name != object_array_slopbuf)
+		free(ent->name);
+}
+
 void object_array_filter(struct object_array *array,
 			 object_array_each_func_t want, void *cb_data)
 {
@@ -367,8 +377,7 @@ void object_array_filter(struct object_array *array,
 				objects[dst] = objects[src];
 			dst++;
 		} else {
-			if (objects[src].name != object_array_slopbuf)
-				free(objects[src].name);
+			object_array_release_entry(&objects[src]);
 		}
 	}
 	array->nr = dst;
@@ -400,8 +409,7 @@ void object_array_remove_duplicates(struct object_array *array)
 				objects[array->nr] = objects[src];
 			array->nr++;
 		} else {
-			if (objects[src].name != object_array_slopbuf)
-				free(objects[src].name);
+			object_array_release_entry(&objects[src]);
 		}
 	}
 }