From 48b644192d73be11d54b4b3dcfe255bd1b47884d Mon Sep 17 00:00:00 2001
From: Conrad Meyer <cem@FreeBSD.org>
Date: Mon, 8 May 2017 15:51:29 +0000
Subject: [PATCH] csplit(1): Fix extraneous output in edge case

When the input to csplit contains fewer lines than the number of matches
specified, extra output was mistakenly included in some output files.

Fix the bug and add a simple ATF regression test.

PR:		219024
Submitted by:	J.R. Oldroyd <fbsd at opal.com>
---
 usr.bin/csplit/Makefile             |  6 +++
 usr.bin/csplit/csplit.c             |  4 +-
 usr.bin/csplit/tests/Makefile       |  7 ++++
 usr.bin/csplit/tests/csplit_test.sh | 60 +++++++++++++++++++++++++++++
 4 files changed, 76 insertions(+), 1 deletion(-)
 create mode 100644 usr.bin/csplit/tests/Makefile
 create mode 100755 usr.bin/csplit/tests/csplit_test.sh

diff --git a/usr.bin/csplit/Makefile b/usr.bin/csplit/Makefile
index 3f370c7c4ad..52b2016b813 100644
--- a/usr.bin/csplit/Makefile
+++ b/usr.bin/csplit/Makefile
@@ -1,5 +1,11 @@
 # $FreeBSD$
 
+.include <src.opts.mk>
+
 PROG=	csplit
 
+.if ${MK_TESTS} != "no"
+SUBDIR+= tests
+.endif
+
 .include <bsd.prog.mk>
diff --git a/usr.bin/csplit/csplit.c b/usr.bin/csplit/csplit.c
index b23c85d23a6..0adecaf82c4 100644
--- a/usr.bin/csplit/csplit.c
+++ b/usr.bin/csplit/csplit.c
@@ -399,8 +399,10 @@ do_rexp(const char *expr)
 		first = 0;
 	}
 
-	if (p == NULL)
+	if (p == NULL) {
+		toomuch(NULL, 0);
 		errx(1, "%s: no match", re);
+	}
 
 	if (ofs <= 0) {
 		/*
diff --git a/usr.bin/csplit/tests/Makefile b/usr.bin/csplit/tests/Makefile
new file mode 100644
index 00000000000..5403cc85d81
--- /dev/null
+++ b/usr.bin/csplit/tests/Makefile
@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+PACKAGE=	tests
+
+ATF_TESTS_SH=	csplit_test
+
+.include <bsd.test.mk>
diff --git a/usr.bin/csplit/tests/csplit_test.sh b/usr.bin/csplit/tests/csplit_test.sh
new file mode 100755
index 00000000000..a47ecd79f01
--- /dev/null
+++ b/usr.bin/csplit/tests/csplit_test.sh
@@ -0,0 +1,60 @@
+# Copyright (c) 2017 Conrad Meyer <cem@FreeBSD.org>
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+# $FreeBSD$
+
+atf_test_case lines_lt_count
+lines_lt_count_head()
+{
+	atf_set "descr" \
+	    "Test an edge case where input has fewer lines than count"
+}
+lines_lt_count_body()
+{
+	cat > expectfile00 << HERE
+one
+two
+HERE
+	cat > expectfile01 << HERE
+xxx 1
+three
+four
+HERE
+	cat > expectfile02 << HERE
+xxx 2
+five
+six
+HERE
+	echo -e "one\ntwo\nxxx 1\nthree\nfour\nxxx 2\nfive\nsix" | \
+	    csplit -k - '/xxx/' '{10}'
+
+	atf_check cmp expectfile00 xx00
+	atf_check cmp expectfile01 xx01
+	atf_check cmp expectfile02 xx02
+}
+
+atf_init_test_cases()
+{
+	atf_add_test_case lines_lt_count
+}