[PATCH v3 1/2] git-am: emit usage when called w/o arguments and w/o patch on stdin

[Jay Soffian <jaysoffian@gmail.com>]

When git am is called w/o arguments, w/o a patch on stdin and the user hits
ctrl-c, it leaves behind a partially populated $dotest directory. After this
commit, it emits usage when called w/o arguments and w/o a patch on stdin.

Noticed by Sverre Rabbelier

Signed-off-by: Jay Soffian <jaysoffian@gmail.com>
---
Change from v2: make Junio happy by no longer removing $dotest if git-am is
interupted while mailsplit is running.

 git-am.sh |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/git-am.sh b/git-am.sh
index b1c05c9..92a64b2 100755
--- a/git-am.sh
+++ b/git-am.sh
@@ -254,6 +254,7 @@ else
 		done
 		shift
 	fi
+	test $# = 0 && test -t 0 && usage
 	git mailsplit -d"$prec" -o"$dotest" -b -- "$@" > "$dotest/last" ||  {
 		rm -fr "$dotest"
 		exit 1
-- 
1.6.1.224.gb56c