diff --git a/ap/libc/glibc/glibc-2.23/posix/bug-regex23.c b/ap/libc/glibc/glibc-2.23/posix/bug-regex23.c
new file mode 100644
index 0000000..2825f8f
--- /dev/null
+++ b/ap/libc/glibc/glibc-2.23/posix/bug-regex23.c
@@ -0,0 +1,34 @@
+/* Test we don't segfault on invalid UTF-8 sequence.
+   Copyright (C) 2004-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jakub Jelinek <jakub@redhat.com>, 2004.
+
+   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 <locale.h>
+#include <regex.h>
+#include <string.h>
+
+int
+main (void)
+{
+  regex_t r;
+
+  memset (&r, 0, sizeof (r));
+  setlocale (LC_ALL, "de_DE.UTF-8");
+  regcomp (&r, "[-a-z_0-9.]+@[-a-z_0-9.]+", REG_EXTENDED | REG_ICASE);
+  regexec (&r, "\xe7\xb7\x95\xe7\x97", 0, NULL, 0);
+  return 0;
+}