[PATCH] format-patch: fix bug with --stdout in a subdirectory

We set the output directory to the git subdirectory prefix if one has
not already been specified. However, in the case of --stdout, we
explicitly _don't_ want the output directory to be set. The result was
that "git-format-patch --stdout" in a directory besides the project root
produced the "standard output, or directory, which one?" error message.

Signed-off-by: Jeff King <redacted>
---
 builtin-log.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/builtin-log.c b/builtin-log.c
index 9691296..d4bf2dc 100644
--- a/builtin-log.c
+++ b/builtin-log.c

@@ -482,7 +482,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	if (!rev.diffopt.text)
 		rev.diffopt.binary = 1;
 
-	if (!output_directory)
+	if (!output_directory && !use_stdout)
 		output_directory = prefix;
 
 	if (output_directory) {

-- 
1.5.0.rc2.g8cad-dirty