Merge branch 'mh/reflife'

Define memory ownership and lifetime rules for what for-each-ref
feeds to its callbacks (in short, "you do not own it, so make a
copy if you want to keep it").

* mh/reflife: (25 commits)
  refs: document the lifetime of the args passed to each_ref_fn
  register_ref(): make a copy of the bad reference SHA-1
  exclude_existing(): set existing_refs.strdup_strings
  string_list_add_refs_by_glob(): add a comment about memory management
  string_list_add_one_ref(): rename first parameter to "refname"
  show_head_ref(): rename first parameter to "refname"
  show_head_ref(): do not shadow name of argument
  add_existing(): do not retain a reference to sha1
  do_fetch(): clean up existing_refs before exiting
  do_fetch(): reduce scope of peer_item
  object_array_entry: fix memory handling of the name field
  find_first_merges(): remove unnecessary code
  find_first_merges(): initialize merges variable using initializer
  fsck: don't put a void*-shaped peg in a char*-shaped hole
  object_array_remove_duplicates(): rewrite to reduce copying
  revision: use object_array_filter() in implementation of gc_boundary()
  object_array: add function object_array_filter()
  revision: split some overly-long lines
  cmd_diff(): make it obvious which cases are exclusive of each other
  cmd_diff(): rename local variable "list" -> "entry"
  ...

1 files changed, 23 insertions, 2 deletions

diff --git a/object.h b/object.h
index 97d384b80..2ff68c52d 100644
--- a/object.h
+++ b/object.h
@@ -11,7 +11,13 @@ struct object_array {
 	unsigned int alloc;
 	struct object_array_entry {
 		struct object *item;
-		const char *name;
+		/*
+		 * name or NULL.  If non-NULL, the memory pointed to
+		 * is owned by this object *except* if it points at
+		 * object_array_slopbuf, which is a static copy of the
+		 * empty string.
+		 */
+		char *name;
 		unsigned mode;
 	} *objects;
 };
@@ -85,7 +91,22 @@ int object_list_contains(struct object_list *list, struct object *obj);
 /* Object array handling .. */
 void add_object_array(struct object *obj, const char *name, struct object_array *array);
 void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode);
-void object_array_remove_duplicates(struct object_array *);
+
+typedef int (*object_array_each_func_t)(struct object_array_entry *, void *);
+
+/*
+ * Apply want to each entry in array, retaining only the entries for
+ * which the function returns true.  Preserve the order of the entries
+ * that are retained.
+ */
+void object_array_filter(struct object_array *array,
+			 object_array_each_func_t want, void *cb_data);
+
+/*
+ * Remove from array all but the first entry with a given name.
+ * Warning: this function uses an O(N^2) algorithm.
+ */
+void object_array_remove_duplicates(struct object_array *array);
 
 void clear_object_flags(unsigned flags);