[PATCH] tests: extend coverage of dfa.c's match_mb_charset

[Jim Meyering]

This adds a test case to increase test coverage
of part of dfa.c (the DFA matcher used by grep and gawk).
While thinking about removing the few remaining uses of strncpy
in dfa.c, I found that none of the existing tests covered
the 40+ lines of code at the end of match_mb_charset, so
constructed this test case to demonstrate that it's not dead code.

>From 02f1daa1e7dc80a544b7904d1d9d9841e02e3d8b Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Sun, 3 Jun 2012 16:29:59 +0200
Subject: [PATCH] tests: extend coverage of dfa.c's match_mb_charset

Add a test case to increase test coverage of part of dfa.c (the DFA
matcher used by grep and gawk).  While thinking about removing the few
remaining uses of strncpy in dfa.c, I found that none of the existing
tests covered the 40+ lines of code at the end of match_mb_charset,
so constructed this test case to demonstrate that it's not dead code
* tests/dfa-coverage: New test, for improved coverage.
* tests/Makefile.am (TESTS): Add it.
---
 tests/Makefile.am  |  1 +
 tests/dfa-coverage | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100755 tests/dfa-coverage

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 167e318..388d48a 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -47,6 +47,7 @@ TESTS =                                               \
   case-fold-char-range                         \
   case-fold-char-type                          \
   char-class-multibyte                         \
+  dfa-coverage                                 \
   dfa-heap-overrun                             \
   dfaexec-multibyte                            \
   empty                                                \
diff --git a/tests/dfa-coverage b/tests/dfa-coverage
new file mode 100755
index 0000000..3b4e7ed
--- /dev/null
+++ b/tests/dfa-coverage
@@ -0,0 +1,32 @@
+#!/bin/sh
+# Exercise the final reachable code in dfa.c's match_mb_charset.
+
+# Copyright (C) 2012 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+
+require_en_utf8_locale_
+require_compiled_in_MB_support
+
+fail=0
+
+echo a > in || framework_failure_
+
+LC_ALL=en_US.UTF-8 grep -E '[^_]|$' in > out || fail=1
+
+compare out in || fail=1
+
+Exit $fail
--
1.7.11.rc2