format-patch: refactor output selection

The --stdout and --output-directory options are mutually exclusive, but
it's hard to tell from reading the code. We have three separate
conditionals that check for use_stdout, and it's only after we've set up
the output_directory fully that we check whether the user also specified
--stdout.

Instead, let's check the exclusion explicitly first, then have a single
conditional that handles stdout versus an output directory. This is
slightly easier to follow now, and also will keep things sane when we
add another output mode in a future patch.

We'll add a few tests as well, covering the mutual exclusion and the
fact that we are not confused by a configured output directory.

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

1 files changed, 13 insertions, 0 deletions

diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index 294e76c860..e8d6156a6a 100755
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -1919,6 +1919,19 @@ test_expect_success 'format-patch -o overrides format.outputDirectory' '
 	test_path_is_dir patchset
 '
 
+test_expect_success 'format-patch forbids multiple outputs' '
+	rm -fr outdir &&
+	test_must_fail \
+		git format-patch --stdout --output-directory=outdir
+'
+
+test_expect_success 'configured outdir does not conflict with output options' '
+	rm -fr outdir &&
+	test_config format.outputDirectory outdir &&
+	git format-patch --stdout &&
+	test_path_is_missing outdir
+'
+
 test_expect_success 'format-patch --base' '
 	git checkout patchid &&