Add more tests for format-patch

Tests -o, and an excessively long subject, and --thread, with and
without --in-reply-to=

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t4014-format-patch.sh

@@ -88,4 +88,49 @@ test_expect_success 'replay did not screw up the log message' '
 
 '
 
+test_expect_success 'multiple files' '
+
+	rm -rf patches/ &&
+	git checkout side &&
+	git format-patch -o patches/ master &&
+	ls patches/0001-Side-changes-1.patch patches/0002-Side-changes-2.patch patches/0003-Side-changes-3-with-n-backslash-n-in-it.patch
+'
+
+test_expect_success 'thread' '
+
+	rm -rf patches/ &&
+	git checkout side &&
+	git format-patch --thread -o patches/ master &&
+	FIRST_MID=$(grep "Message-Id:" patches/0001-* | sed "s/^[^<]*\(<[^>]*>\).*$/\1/") &&
+	for i in patches/0002-* patches/0003-*
+	do
+	  grep "References: $FIRST_MID" $i &&
+	  grep "In-Reply-To: $FIRST_MID" $i
+	done
+'
+
+test_expect_success 'thread in-reply-to' '
+
+	rm -rf patches/ &&
+	git checkout side &&
+	git format-patch --in-reply-to="<test.message>" --thread -o patches/ master &&
+	FIRST_MID="<test.message>" &&
+	for i in patches/*
+	do
+	  grep "References: $FIRST_MID" $i &&
+	  grep "In-Reply-To: $FIRST_MID" $i
+	done
+'
+
+test_expect_success 'excessive subject' '
+
+	rm -rf patches/ &&
+	git checkout side &&
+	for i in 5 6 1 2 3 A 4 B C 7 8 9 10 D E F; do echo "$i"; done >>file &&
+	git update-index file &&
+	git commit -m "This is an excessively long subject line for a message due to the habit some projects have of not having a short, one-line subject at the start of the commit message, but rather sticking a whole paragraph right at the start as the only thing in the commit message. It had better not become the filename for the patch." &&
+	git format-patch -o patches/ master..side &&
+	ls patches/0004-This-is-an-excessively-long-subject-line-for-a-messa.patch
+'
+
 test_done