add: create ADD_EDIT.patch with mode 0666

We should be letting the user's umask take care of
restricting permissions. Even though this is a temporary
file and probably nobody would notice, this brings us in
line with other temporary file creations in git (e.g.,
choosing "e"dit from git-add--interactive).

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

builtin/add.c

@@ -281,7 +281,7 @@ static int edit_patch(int argc, const char **argv, const char *prefix)
 	argc = setup_revisions(argc, argv, &rev, NULL);
 	rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 	DIFF_OPT_SET(&rev.diffopt, IGNORE_DIRTY_SUBMODULES);
-	out = open(file, O_CREAT | O_WRONLY, 0644);
+	out = open(file, O_CREAT | O_WRONLY, 0666);
 	if (out < 0)
 		die (_("Could not open '%s' for writing."), file);
 	rev.diffopt.file = xfdopen(out, "w");