posix: Sync gnulib regex implementation

This patch syncs the regex implementation with gnulib (commit 0ee5212).
Only two changes in GLIBC regex testing are required:

  1. posix/bug-regex28.c: as previously discussed [1] the change of
     expected results on the pattern should be safe.

  2. posix/PCRE.tests: the ERE (a)|\1 is malformed (in the sense that
     the \1 doesn't mean anything) and although current GLIBC accepts
     it has undefined behavior.  This patch removes the specific test.

This sync contains some patches from thread 'Regex: Make libc regex
more usable outside GLIBC.' [2] which have been pushed upstream in
gnulib.  This patches also fixes some regex issues (BZ #23233,
BZ #21163, BZ #18986, BZ #13762) and I did not add testcases for
both #23233 and #13762 because I couldn't think a simple way to
trigger the expected failure path to trigger them.

Checked on x86_64-linux-gnu and i686-linux-gnu.

	[BZ #23233]
	[BZ #21163]
	[BZ #18986]
	[BZ #13762]
	* posix/Makefile (tests): Add bug-regex37 and bug-regex38.
	* posix/PCRE.tests: Remove invalid test.
	* posix/bug-regex28.c: Fix expected values for used syntax.
	* posix/bug-regex37.c: New file.
	* posix/bug-regex38.c: Likewise.
	* posix/regcomp.c: Sync with gnulib.
	* posix/regex.c: Likewise.
	* posix/regex.h: Likewise.
	* posix/regex_internal.c: Likewise.
	* posix/regex_internal.h: Likewise.
	* posix/regexec.c: Likewise.

[1] https://sourceware.org/ml/libc-alpha/2017-12/msg00807.html
[2] https://sourceware.org/ml/libc-alpha/2017-12/msg00237.html

1 files changed, 32 insertions, 0 deletions

diff --git a/posix/bug-regex38.c b/posix/bug-regex38.c
new file mode 100644
index 0000000000..cb0eb7d214
--- /dev/null
+++ b/posix/bug-regex38.c
@@ -0,0 +1,32 @@
+/* Diagnose invalid back-reference in the ERE '()|\1' (BZ #18986).
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <regex.h>
+
+#include <support/check.h>
+
+static int
+do_test (void)
+{
+  char const pattern[] = "0|()0|\\1|0";
+  regex_t r;
+  TEST_VERIFY_EXIT (regcomp (&r, pattern, REG_EXTENDED) == REG_ESUBREG);
+  return 0;
+}
+
+#include <support/test-driver.c>