diff --git a/ap/libc/glibc/glibc-2.23/posix/bug-regex20.c b/ap/libc/glibc/glibc-2.23/posix/bug-regex20.c
new file mode 100644
index 0000000..70fd307
--- /dev/null
+++ b/ap/libc/glibc/glibc-2.23/posix/bug-regex20.c
@@ -0,0 +1,286 @@
+/* Test for UTF-8 regular expression optimizations.
+   Copyright (C) 2003-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
+
+   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 <sys/types.h>
+#include <mcheck.h>
+#include <regex.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <locale.h>
+
+#define RE_NO_INTERNAL_PROTOTYPES 1
+#include "regex_internal.h"
+
+#define BRE RE_SYNTAX_POSIX_BASIC
+#define ERE RE_SYNTAX_POSIX_EXTENDED
+
+static struct
+{
+  int syntax;
+  const char *pattern;
+  const char *string;
+  int res, optimize;
+} tests[] = {
+  /* \xc3\x84		LATIN CAPITAL LETTER A WITH DIAERESIS
+     \xc3\x96		LATIN CAPITAL LETTER O WITH DIAERESIS
+     \xc3\xa4		LATIN SMALL LETTER A WITH DIAERESIS
+     \xc3\xb6		LATIN SMALL LETTER O WITH DIAERESIS
+     \xe2\x80\x94	EM DASH  */
+  /* Should be optimized.  */
+  {BRE, "foo", "b\xc3\xa4rfoob\xc3\xa4z", 4, 1},
+  {BRE, "b\xc3\xa4z", "b\xc3\xa4rfoob\xc3\xa4z", 7, 1},
+  {BRE, "b\xc3\xa4*z", "b\xc3\xa4rfoob\xc3\xa4z", 7, 1},
+  {BRE, "b\xc3\xa4*z", "b\xc3\xa4rfoobz", 7, 1},
+  {BRE, "b\xc3\xa4\\+z", "b\xc3\xa4rfoob\xc3\xa4\xc3\xa4z", 7, 1},
+  {BRE, "b\xc3\xa4\\?z", "b\xc3\xa4rfoob\xc3\xa4z", 7, 1},
+  {BRE, "b\xc3\xa4\\{1,2\\}z", "b\xc3\xa4rfoob\xc3\xa4z", 7, 1},
+  {BRE, "^x\\|xy*z$", "\xc3\xb6xyyz", 2, 1},
+  {BRE, "^x\\\\y\\{6\\}z\\+", "x\\yyyyyyzz\xc3\xb6", 0, 1},
+  {BRE, "^x\\\\y\\{2,36\\}z\\+", "x\\yzz\xc3\xb6", -1, 1},
+  {BRE, "^x\\\\y\\{,3\\}z\\+", "x\\yyyzz\xc3\xb6", 0, 1},
+  {BRE, "^x\\|x\xc3\xa4*z$", "\xc3\xb6x\xc3\xa4\xc3\xa4z", 2, 1},
+  {BRE, "^x\\\\\xc3\x84\\{6\\}z\\+",
+   "x\\\xc3\x84\xc3\x84\xc3\x84\xc3\x84\xc3\x84\xc3\x84zz\xc3\xb6", 0, 1},
+  {BRE, "^x\\\\\xc3\x84\\{2,36\\}z\\+", "x\\\xc3\x84zz\xc3\xb6", -1, 1},
+  {BRE, "^x\\\\\xc3\x84\\{,3\\}z\\+",
+   "x\\\xc3\x84\xc3\x84\xc3\x84zz\xc3\xb6", 0, 1},
+  {BRE, "x[C]y", "axCy", 1, 1},
+  {BRE, "x[ABC]y", "axCy", 1, 1},
+  {BRE, "\\`x\\|z\\'", "x\xe2\x80\x94", 0, 1},
+  {BRE, "\\(xy\\)z\\1a\\1", "\xe2\x80\x94xyzxyaxy\xc3\x84", 3, 1},
+  {BRE, "xy\\?z", "\xc3\x84xz\xc3\xb6", 2, 1},
+  {BRE, "\\`\xc3\x84\\|z\\'", "\xc3\x84\xe2\x80\x94", 0, 1},
+  {BRE, "\\(x\xc3\x84\\)z\\1\x61\\1",
+   "\xe2\x80\x94x\xc3\x84zx\xc3\x84\x61x\xc3\x84\xc3\x96", 3, 1},
+  {BRE, "x\xc3\x96\\?z", "\xc3\x84xz\xc3\xb6", 2, 1},
+  {BRE, "x.y", "ax\xe2\x80\x94yz", 1, 1},
+  {BRE, "x.*z", "\xc3\x84xz", 2, 1},
+  {BRE, "x.*z", "\xc3\x84x\xe2\x80\x94z", 2, 1},
+  {BRE, "x.*z", "\xc3\x84x\xe2\x80\x94y\xf1\x90\x80\x90z", 2, 1},
+  {BRE, "x.*z", "\xc3\x84x\xe2\x80\x94\xc3\x94\xf1\x90\x80\x90z", 2, 1},
+  {BRE, "x.\\?z", "axz", 1, 1},
+  {BRE, "x.\\?z", "axyz", 1, 1},
+  {BRE, "x.\\?z", "ax\xc3\x84z", 1, 1},
+  {BRE, "x.\\?z", "ax\xe2\x80\x94z", 1, 1},
+  {BRE, "x.\\?z", "ax\xf0\x9d\x80\x80z", 1, 1},
+  {BRE, "x.\\?z", "ax\xf9\x81\x82\x83\x84z", 1, 1},
+  {BRE, "x.\\?z", "ax\xfd\xbf\xbf\xbf\xbf\xbfz", 1, 1},
+  {BRE, ".", "y", 0, 1},
+  {BRE, ".", "\xc3\x84", 0, 1},
+  {BRE, ".", "\xe2\x80\x94", 0, 1},
+  {BRE, ".", "\xf0\x9d\x80\x80", 0, 1},
+  {BRE, ".", "\xf9\x81\x82\x83\x84", 0, 1},
+  {BRE, ".", "\xfd\xbf\xbf\xbf\xbf\xbf", 0, 1},
+  {BRE, "x.\\?z", "axyyz", -1, 1},
+  {BRE, "x.\\?z", "ax\xc3\x84\xc3\x96z", -1, 1},
+  {BRE, "x.\\?z", "ax\xe2\x80\x94\xc3\xa4z", -1, 1},
+  {BRE, "x.\\?z", "ax\xf0\x9d\x80\x80yz", -1, 1},
+  {BRE, "x.\\?z", "ax\xf9\x81\x82\x83\x84\xf0\x9d\x80\x81z", -1, 1},
+  {BRE, "x.\\?z", "ax\xfd\xbf\xbf\xbf\xbf\xbf\xc3\x96z", -1, 1},
+  {BRE, "x.\\+z", "\xe2\x80\x94xz", -1, 1},
+  {BRE, "x.\\+z", "\xe2\x80\x94xyz", 3, 1},
+  {BRE, "x.\\+z", "\xe2\x80\x94x\xc3\x84y\xe2\x80\x94z", 3, 1},
+  {BRE, "x.\\+z", "\xe2\x80\x94x\xe2\x80\x94z", 3, 1},
+  {BRE, "x.\\+z", "\xe2\x80\x94x\xf0\x9d\x80\x80\xc3\x84z", 3, 1},
+  {BRE, "x.\\+z", "\xe2\x80\x94x.~\xe2\x80\x94\xf9\x81\x82\x83\x84z", 3, 1},
+  {BRE, "x.\\+z", "\xe2\x80\x94x\xfd\xbf\xbf\xbf\xbf\xbfz", 3, 1},
+  {BRE, "x.\\{1,2\\}z", "\xe2\x80\x94xz", -1, 1},
+  {BRE, "x.\\{1,2\\}z", "\xe2\x80\x94x\xc3\x96y\xc3\xa4z", -1, 1},
+  {BRE, "x.\\{1,2\\}z", "\xe2\x80\x94xyz", 3, 1},
+  {BRE, "x.\\{1,2\\}z", "\xe2\x80\x94x\xc3\x84\xe2\x80\x94z", 3, 1},
+  {BRE, "x.\\{1,2\\}z", "\xe2\x80\x94x\xe2\x80\x94z", 3, 1},
+  {BRE, "x.\\{1,2\\}z", "\xe2\x80\x94x\xf0\x9d\x80\x80\xc3\x84z", 3, 1},
+  {BRE, "x.\\{1,2\\}z", "\xe2\x80\x94x~\xe2\x80\x94z", 3, 1},
+  {BRE, "x.\\{1,2\\}z", "\xe2\x80\x94x\xfd\xbf\xbf\xbf\xbf\xbfz", 3, 1},
+  {BRE, "x\\(.w\\|\xc3\x86\\)\\?z", "axz", 1, 1},
+  {BRE, "x\\(.w\\|\xc3\x86\\)\\?z", "ax\xfd\xbf\xbf\xbf\xbf\xbfwz", 1, 1},
+  {BRE, "x\\(.w\\|\xc3\x86\\)\\?z", "ax\xc3\x86z", 1, 1},
+  {BRE, "x\\(.w\\|\xc3\x86\\)\\?z", "ax\xe2\x80\x96wz", 1, 1},
+  {ERE, "foo", "b\xc3\xa4rfoob\xc3\xa4z", 4, 1},
+  {ERE, "^x|xy*z$", "\xc3\xb6xyyz", 2, 1},
+  {ERE, "^x\\\\y{6}z+", "x\\yyyyyyzz\xc3\xb6", 0, 1},
+  {ERE, "^x\\\\y{2,36}z+", "x\\yzz\xc3\xb6", -1, 1},
+  {ERE, "^x\\\\y{,3}z+", "x\\yyyzz\xc3\xb6", 0, 1},
+  {ERE, "x[C]y", "axCy", 1, 1},
+  {ERE, "x[ABC]y", "axCy", 1, 1},
+  {ERE, "\\`x|z\\'", "x\xe2\x80\x94", 0, 1},
+  {ERE, "(xy)z\\1a\\1", "\xe2\x80\x94xyzxyaxy\xc3\x84", 3, 1},
+  {ERE, "xy?z", "\xc3\x84xz\xc3\xb6", 2, 1},
+  {ERE, "x.y", "ax\xe2\x80\x94yz", 1, 1},
+  {ERE, "x.*z", "\xc3\x84xz", 2, 1},
+  {ERE, "x.*z", "\xc3\x84x\xe2\x80\x94z", 2, 1},
+  {ERE, "x.*z", "\xc3\x84x\xe2\x80\x94y\xf1\x90\x80\x90z", 2, 1},
+  {ERE, "x.*z", "\xc3\x84x\xe2\x80\x94\xc3\x94\xf1\x90\x80\x90z", 2, 1},
+  {ERE, "x.?z", "axz", 1, 1},
+  {ERE, "x.?z", "axyz", 1, 1},
+  {ERE, "x.?z", "ax\xc3\x84z", 1, 1},
+  {ERE, "x.?z", "ax\xe2\x80\x94z", 1, 1},
+  {ERE, "x.?z", "ax\xf0\x9d\x80\x80z", 1, 1},
+  {ERE, "x.?z", "ax\xf9\x81\x82\x83\x84z", 1, 1},
+  {ERE, "x.?z", "ax\xfd\xbf\xbf\xbf\xbf\xbfz", 1, 1},
+  {ERE, "x.?z", "axyyz", -1, 1},
+  {ERE, "x.?z", "ax\xc3\x84\xc3\x96z", -1, 1},
+  {ERE, "x.?z", "ax\xe2\x80\x94\xc3\xa4z", -1, 1},
+  {ERE, "x.?z", "ax\xf0\x9d\x80\x80yz", -1, 1},
+  {ERE, "x.?z", "ax\xf9\x81\x82\x83\x84\xf0\x9d\x80\x81z", -1, 1},
+  {ERE, "x.?z", "ax\xfd\xbf\xbf\xbf\xbf\xbf\xc3\x96z", -1, 1},
+  {ERE, "x.+z", "\xe2\x80\x94xz", -1, 1},
+  {ERE, "x.+z", "\xe2\x80\x94xyz", 3, 1},
+  {ERE, "x.+z", "\xe2\x80\x94x\xc3\x84y\xe2\x80\x94z", 3, 1},
+  {ERE, "x.+z", "\xe2\x80\x94x\xe2\x80\x94z", 3, 1},
+  {ERE, "x.+z", "\xe2\x80\x94x\xf0\x9d\x80\x80\xc3\x84z", 3, 1},
+  {ERE, "x.+z", "\xe2\x80\x94x.~\xe2\x80\x94\xf9\x81\x82\x83\x84z", 3, 1},
+  {ERE, "x.+z", "\xe2\x80\x94x\xfd\xbf\xbf\xbf\xbf\xbfz", 3, 1},
+  {ERE, "x.{1,2}z", "\xe2\x80\x94xz", -1, 1},
+  {ERE, "x.{1,2}z", "\xe2\x80\x94x\xc3\x96y\xc3\xa4z", -1, 1},
+  {ERE, "x.{1,2}z", "\xe2\x80\x94xyz", 3, 1},
+  {ERE, "x.{1,2}z", "\xe2\x80\x94x\xc3\x84\xe2\x80\x94z", 3, 1},
+  {ERE, "x.{1,2}z", "\xe2\x80\x94x\xe2\x80\x94z", 3, 1},
+  {ERE, "x.{1,2}z", "\xe2\x80\x94x\xf0\x9d\x80\x80\xc3\x84z", 3, 1},
+  {ERE, "x.{1,2}z", "\xe2\x80\x94x~\xe2\x80\x94z", 3, 1},
+  {ERE, "x.{1,2}z", "\xe2\x80\x94x\xfd\xbf\xbf\xbf\xbf\xbfz", 3, 1},
+  {ERE, "x(.w|\xc3\x86)?z", "axz", 1, 1},
+  {ERE, "x(.w|\xc3\x86)?z", "ax\xfd\xbf\xbf\xbf\xbf\xbfwz", 1, 1},
+  {ERE, "x(.w|\xc3\x86)?z", "ax\xc3\x86z", 1, 1},
+  {ERE, "x(.w|\xc3\x86)?z", "ax\xe2\x80\x96wz", 1, 1},
+  /* Should not be optimized.  */
+  {BRE, "x[\xc3\x84\xc3\xa4]y", "ax\xc3\xa4y", 1, 0},
+  {BRE, "x[A-Z,]y", "axCy", 1, 0},
+  {BRE, "x[^y]z", "ax\xe2\x80\x94z", 1, 0},
+  {BRE, "x[[:alnum:]]z", "ax\xc3\x96z", 1, 0},
+  {BRE, "x[[=A=]]z", "axAz", 1, 0},
+  {BRE, "x[[=\xc3\x84=]]z", "ax\xc3\x84z", 1, 0},
+  {BRE, "\\<g", "\xe2\x80\x94g", 3, 0},
+  {BRE, "\\bg\\b", "\xe2\x80\x94g", 3, 0},
+  {BRE, "\\Bg\\B", "\xc3\xa4g\xc3\xa4", 2, 0},
+  {BRE, "a\\wz", "a\xc3\x84z", 0, 0},
+  {BRE, "x\\Wz", "\xc3\x96x\xe2\x80\x94z", 2, 0},
+  {ERE, "x[\xc3\x84\xc3\xa4]y", "ax\xc3\xa4y", 1, 0},
+  {ERE, "x[A-Z,]y", "axCy", 1, 0},
+  {ERE, "x[^y]z", "ax\xe2\x80\x94z", 1, 0},
+  {ERE, "x[[:alnum:]]z", "ax\xc3\x96z", 1, 0},
+  {ERE, "x[[=A=]]z", "axAz", 1, 0},
+  {ERE, "x[[=\xc3\x84=]]z", "ax\xc3\x84z", 1, 0},
+  {ERE, "\\<g", "\xe2\x80\x94g", 3, 0},
+  {ERE, "\\bg\\b", "\xe2\x80\x94g", 3, 0},
+  {ERE, "\\Bg\\B", "\xc3\xa4g\xc3\xa4", 2, 0},
+  {ERE, "a\\wz", "a\xc3\x84z", 0, 0},
+  {ERE, "x\\Wz", "\xc3\x96x\xe2\x80\x94z", 2, 0},
+};
+
+int
+main (void)
+{
+  struct re_pattern_buffer regbuf;
+  const char *err;
+  size_t i;
+  int ret = 0;
+
+  mtrace ();
+
+  setlocale (LC_ALL, "de_DE.UTF-8");
+  for (i = 0; i < sizeof (tests) / sizeof (tests[0]); ++i)
+    {
+      int res, optimized;
+
+      re_set_syntax (tests[i].syntax);
+      memset (&regbuf, '\0', sizeof (regbuf));
+      err = re_compile_pattern (tests[i].pattern, strlen (tests[i].pattern),
+                                &regbuf);
+      if (err != NULL)
+	{
+	  printf ("re_compile_pattern failed: %s\n", err);
+	  ret = 1;
+	  continue;
+	}
+
+      /* Check if re_search will be done as multi-byte or single-byte.  */
+      optimized = ((re_dfa_t *) regbuf.buffer)->mb_cur_max == 1;
+      if (optimized != tests[i].optimize)
+        {
+          printf ("pattern %zd %soptimized while it should%s be\n",
+		  i, optimized ? "" : "not ", tests[i].optimize ? "" : " not");
+	  ret = 1;
+        }
+
+      int str_len = strlen (tests[i].string);
+      res = re_search (&regbuf, tests[i].string, str_len, 0, str_len, NULL);
+      if (res != tests[i].res)
+	{
+	  printf ("re_search %zd failed: %d\n", i, res);
+	  ret = 1;
+	  regfree (&regbuf);
+	  continue;
+	}
+
+      res = re_search (&regbuf, tests[i].string, str_len, str_len, -str_len,
+		       NULL);
+      if (res != tests[i].res)
+	{
+	  printf ("backward re_search %zd failed: %d\n", i, res);
+	  ret = 1;
+	  regfree (&regbuf);
+	  continue;
+	}
+      regfree (&regbuf);
+
+      re_set_syntax (tests[i].syntax | RE_ICASE);
+      memset (&regbuf, '\0', sizeof (regbuf));
+      err = re_compile_pattern (tests[i].pattern, strlen (tests[i].pattern),
+                                &regbuf);
+      if (err != NULL)
+	{
+	  printf ("re_compile_pattern failed: %s\n", err);
+	  ret = 1;
+	  continue;
+	}
+
+      /* Check if re_search will be done as multi-byte or single-byte.  */
+      optimized = ((re_dfa_t *) regbuf.buffer)->mb_cur_max == 1;
+      if (optimized)
+        {
+          printf ("pattern %zd optimized while it should not be when case insensitive\n",
+		  i);
+	  ret = 1;
+        }
+
+      res = re_search (&regbuf, tests[i].string, str_len, 0, str_len, NULL);
+      if (res != tests[i].res)
+	{
+	  printf ("ICASE re_search %zd failed: %d\n", i, res);
+	  ret = 1;
+	  regfree (&regbuf);
+	  continue;
+	}
+
+      res = re_search (&regbuf, tests[i].string, str_len, str_len, -str_len,
+		       NULL);
+      if (res != tests[i].res)
+	{
+	  printf ("ICASE backward re_search %zd failed: %d\n", i, res);
+	  ret = 1;
+	  regfree (&regbuf);
+	  continue;
+	}
+      regfree (&regbuf);
+    }
+
+  return ret;
+}