builtin/commit.c: set status_format _after_ option parsing

'git status' should use --porcelain output format when -z is given.
It was not doing so since the _effect_ of using -z, namely that
null_termination would be set, was being checked _before_ option parsing
was performed.

So, move the check so that it is performed after option parsing.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-commit.c

@@ -1039,14 +1039,15 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 		OPT_END(),
 	};
 
-	if (null_termination && status_format == STATUS_FORMAT_LONG)
-		status_format = STATUS_FORMAT_PORCELAIN;
-
 	wt_status_prepare(&s);
 	git_config(git_status_config, &s);
 	argc = parse_options(argc, argv, prefix,
 			     builtin_status_options,
 			     builtin_status_usage, 0);
+
+	if (null_termination && status_format == STATUS_FORMAT_LONG)
+		status_format = STATUS_FORMAT_PORCELAIN;
+
 	handle_untracked_files_arg(&s);
 
 	if (*argv)

t/t7508-status.sh

@@ -364,7 +364,7 @@ test_expect_success 'status submodule summary (clean submodule)' '
 	test_cmp expect output
 '
 
-test_expect_failure 'status -z implies porcelain' '
+test_expect_success 'status -z implies porcelain' '
 	git status --porcelain |
 	perl -pe "s/\012/\000/g" >expect &&
 	git status -z >output &&