Merge branch 'ar/maint-mksnpath' into maint

* ar/maint-mksnpath:
  Use git_pathdup instead of xstrdup(git_path(...))
  git_pathdup: returns xstrdup-ed copy of the formatted path
  Fix potentially dangerous use of git_path in ref.c
  Add git_snpath: a .git path formatting routine with output buffer
  Fix potentially dangerous uses of mkpath and git_path
  Fix mkpath abuse in dwim_ref and dwim_log of sha1_name.c
  Add mksnpath which allows you to specify the output buffer

Conflicts:
	builtin-revert.c
	rerere.c

builtin-revert.c

@@ -269,7 +269,7 @@ static int revert_or_cherry_pick(int argc, const char **argv)
 	int i;
 	char *oneline, *reencoded_message = NULL;
 	const char *message, *encoding;
-	char *defmsg = xstrdup(git_path("MERGE_MSG"));
+	char *defmsg = git_pathdup("MERGE_MSG");
 
 	git_config(git_default_config, NULL);
 	me = action == REVERT ? "revert" : "cherry-pick";