parseopt: add OPT_NEGBIT

On Thu, May 07, 2009 at 09:44:17PM +0200, René Scharfe wrote:
Subject: [PATCH] ls-files: make --no-empty-directory properly negatable

This option was specified to parseopt as an OPT_BIT; however, we
actually want to _set_ the bit on --no-empty-directory. Thus the
existing implementation used --no-empty-directory, and required
--no-no-empty-directory to negate it.

Now that OPT_NEGBIT exists, we can properly support it as
--empty-directory and --no-empty-directory (but of course
still defaulting to showing empty directories).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-ls-files.c

@@ -454,7 +454,7 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
 		OPT_BIT(0, "directory", &dir.flags,
 			"show 'other' directories' name only",
 			DIR_SHOW_OTHER_DIRECTORIES),
-		OPT_BIT(0, "no-empty-directory", &dir.flags,
+		OPT_NEGBIT(0, "empty-directory", &dir.flags,
 			"don't show empty directories",
 			DIR_HIDE_EMPTY_DIRECTORIES),
 		OPT_BOOLEAN('u', "unmerged", &show_unmerged,