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, 38 insertions, 26 deletions

diff --git a/revision.c b/revision.c
index 9318b7d76..f1bb731fd 100644
--- a/revision.c
+++ b/revision.c
@@ -71,7 +71,8 @@ static int show_path_truncated(FILE *out, const struct name_path *path)
 	return ours || emitted;
 }
 
-void show_object_with_name(FILE *out, struct object *obj, const struct name_path *path, const char *component)
+void show_object_with_name(FILE *out, struct object *obj,
+			   const struct name_path *path, const char *component)
 {
 	struct name_path leaf;
 	leaf.up = (struct name_path *)path;
@@ -88,7 +89,9 @@ void add_object(struct object *obj,
 		struct name_path *path,
 		const char *name)
 {
-	add_object_array(obj, path_name(path, name), p);
+	char *pn = path_name(path, name);
+	add_object_array(obj, pn, p);
+	free(pn);
 }
 
 static void mark_blob_uninteresting(struct blob *blob)
@@ -187,7 +190,9 @@ void mark_parents_uninteresting(struct commit *commit)
 	}
 }
 
-static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
+static void add_pending_object_with_mode(struct rev_info *revs,
+					 struct object *obj,
+					 const char *name, unsigned mode)
 {
 	if (!obj)
 		return;
@@ -210,7 +215,8 @@ static void add_pending_object_with_mode(struct rev_info *revs, struct object *o
 	add_object_array_with_mode(obj, name, &revs->pending, mode);
 }
 
-void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
+void add_pending_object(struct rev_info *revs,
+			struct object *obj, const char *name)
 {
 	add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 }
@@ -227,7 +233,9 @@ void add_head_to_pending(struct rev_info *revs)
 	add_pending_object(revs, obj, "HEAD");
 }
 
-static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
+static struct object *get_reference(struct rev_info *revs, const char *name,
+				    const unsigned char *sha1,
+				    unsigned int flags)
 {
 	struct object *object;
 
@@ -248,7 +256,8 @@ void add_pending_sha1(struct rev_info *revs, const char *name,
 	add_pending_object(revs, object, name);
 }
 
-static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
+static struct commit *handle_commit(struct rev_info *revs,
+				    struct object *object, const char *name)
 {
 	unsigned long flags = object->flags;
 
@@ -443,7 +452,8 @@ static void file_change(struct diff_options *options,
 	DIFF_OPT_SET(options, HAS_CHANGES);
 }
 
-static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
+static int rev_compare_tree(struct rev_info *revs,
+			    struct commit *parent, struct commit *commit)
 {
 	struct tree *t1 = parent->tree;
 	struct tree *t2 = commit->tree;
@@ -1129,6 +1139,10 @@ static int limit_list(struct rev_info *revs)
 	return 0;
 }
 
+/*
+ * Add an entry to refs->cmdline with the specified information.
+ * *name is copied.
+ */
 static void add_rev_cmdline(struct rev_info *revs,
 			    struct object *item,
 			    const char *name,
@@ -1140,7 +1154,7 @@ static void add_rev_cmdline(struct rev_info *revs,
 
 	ALLOC_GROW(info->rev, nr + 1, info->alloc);
 	info->rev[nr].item = item;
-	info->rev[nr].name = name;
+	info->rev[nr].name = xstrdup(name);
 	info->rev[nr].whence = whence;
 	info->rev[nr].flags = flags;
 	info->nr++;
@@ -1526,7 +1540,7 @@ static void read_revisions_from_stdin(struct rev_info *revs,
 			}
 			die("options not supported in --stdin mode");
 		}
-		if (handle_revision_arg(xstrdup(sb.buf), revs, 0,
+		if (handle_revision_arg(sb.buf, revs, 0,
 					REVARG_CANNOT_BE_FILENAME))
 			die("bad revision '%s'", sb.buf);
 	}
@@ -2853,25 +2867,23 @@ static struct commit *get_revision_1(struct rev_info *revs)
 	return NULL;
 }
 
-static void gc_boundary(struct object_array *array)
+/*
+ * Return true for entries that have not yet been shown.  (This is an
+ * object_array_each_func_t.)
+ */
+static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
 {
-	unsigned nr = array->nr;
-	unsigned alloc = array->alloc;
-	struct object_array_entry *objects = array->objects;
+	return !(entry->item->flags & SHOWN);
+}
 
-	if (alloc <= nr) {
-		unsigned i, j;
-		for (i = j = 0; i < nr; i++) {
-			if (objects[i].item->flags & SHOWN)
-				continue;
-			if (i != j)
-				objects[j] = objects[i];
-			j++;
-		}
-		for (i = j; i < nr; i++)
-			objects[i].item = NULL;
-		array->nr = j;
-	}
+/*
+ * If array is on the verge of a realloc, garbage-collect any entries
+ * that have already been shown to try to free up some space.
+ */
+static void gc_boundary(struct object_array *array)
+{
+	if (array->nr == array->alloc)
+		object_array_filter(array, entry_unshown, NULL);
 }
 
 static void create_boundary_commit_list(struct rev_info *revs)