Merge branch 'jk/tighten-alloc'

Update various codepaths to avoid manually-counted malloc().

* jk/tighten-alloc: (22 commits)
  ewah: convert to REALLOC_ARRAY, etc
  convert ewah/bitmap code to use xmalloc
  diff_populate_gitlink: use a strbuf
  transport_anonymize_url: use xstrfmt
  git-compat-util: drop mempcpy compat code
  sequencer: simplify memory allocation of get_message
  test-path-utils: fix normalize_path_copy output buffer size
  fetch-pack: simplify add_sought_entry
  fast-import: simplify allocation in start_packfile
  write_untracked_extension: use FLEX_ALLOC helper
  prepare_{git,shell}_cmd: use argv_array
  use st_add and st_mult for allocation size computation
  convert trivial cases to FLEX_ARRAY macros
  use xmallocz to avoid size arithmetic
  convert trivial cases to ALLOC_ARRAY
  convert manual allocations to argv_array
  argv-array: add detach function
  add helpers for allocating flex-array structs
  harden REALLOC_ARRAY and xcalloc against size_t overflow
  tree-diff: catch integer overflow in combine_diff_path allocation
  ...

notes.c

@@ -1035,7 +1035,7 @@ struct notes_tree **load_notes_trees(struct string_list *refs, int flags)
 	struct string_list_item *item;
 	int counter = 0;
 	struct notes_tree **trees;
-	trees = xmalloc((refs->nr+1) * sizeof(struct notes_tree *));
+	ALLOC_ARRAY(trees, refs->nr + 1);
 	for_each_string_list_item(item, refs) {
 		struct notes_tree *t = xcalloc(1, sizeof(struct notes_tree));
 		init_notes(t, item->string, combine_notes_ignore, flags);