Update from Gnulib

This incorporates:
2018-12-16 regex: propagate fix for glibc bug 18040
2018-12-16 obstack, libc-config: Support HP-UX cc in C99 mode
2018-12-15 regex: work around a bug in glibc-2.27 and prior
2018-12-13 localtime-buffer: Avoid endless recursion
* build-aux/config.guess, build-aux/config.sub, lib/cdefs.h:
* lib/gettext.h, lib/localtime-buffer.c, lib/regexec.c, m4/regex.m4:
Copy from Gnulib.

build-aux/config.guess

@@ -2,7 +2,7 @@
 # Attempt to guess a canonical system name.
 #   Copyright 1992-2018 Free Software Foundation, Inc.
 
-timestamp='2018-11-28'
+timestamp='2018-12-07'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -96,8 +96,7 @@ fi
 
 tmp=
 # shellcheck disable=SC2172
-trap 'test -z "$tmp" || rm -fr "$tmp"' 1 2 13 15
-trap 'exitcode=$?; test -z "$tmp" || rm -fr "$tmp"; exit $exitcode' 0
+trap 'test -z "$tmp" || rm -fr "$tmp"' 0 1 2 13 15
 
 set_cc_for_build() {
     : "${TMPDIR=/tmp}"

build-aux/config.sub

@@ -2,7 +2,7 @@
 # Configuration validation subroutine script.
 #   Copyright 1992-2018 Free Software Foundation, Inc.
 
-timestamp='2018-11-28'
+timestamp='2018-12-16'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -111,7 +111,7 @@ case $# in
 esac
 
 # Split fields of configuration type
-IFS="-" read -r field1 field2 field3 field4 <<EOF
+IFS="-" read field1 field2 field3 field4 <<EOF
 $1
 EOF
 
@@ -918,7 +918,7 @@ case $basic_machine in
 		;;
 
 	*-*)
-		IFS="-" read -r cpu vendor <<EOF
+		IFS="-" read cpu vendor <<EOF
 $basic_machine
 EOF
 		;;

lib/cdefs.h

@@ -139,7 +139,7 @@
    Headers that should use flexible arrays only if they're "real"
    (e.g. only if they won't affect sizeof()) should test
    #if __glibc_c99_flexarr_available.  */
-#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
+#if defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L && !defined __HP_cc
 # define __flexarr	[]
 # define __glibc_c99_flexarr_available 1
 #elif __GNUC_PREREQ (2,97)

lib/gettext.h

@@ -185,7 +185,7 @@ npgettext_aux (const char *domain,
 #include <string.h>
 
 #if (((__GNUC__ >= 3 || __GNUG__ >= 2) && !defined __STRICT_ANSI__) \
-     /* || __STDC_VERSION__ == 199901L
+     /* || (__STDC_VERSION__ == 199901L && !defined __HP_cc)
         || (__STDC_VERSION__ >= 201112L && !defined __STDC_NO_VLA__) */ )
 # define _LIBGETTEXT_HAVE_VARIABLE_SIZE_ARRAYS 1
 #else

lib/localtime-buffer.c

@@ -34,6 +34,7 @@ struct tm *localtime_buffer_addr = &tm_zero_buffer;
 
 struct tm *
 rpl_localtime (time_t const *timep)
+#undef localtime
 {
   struct tm *tm = localtime (timep);
 
@@ -46,6 +47,7 @@ rpl_localtime (time_t const *timep)
 /* Same as above, since gmtime and localtime use the same buffer.  */
 struct tm *
 rpl_gmtime (time_t const *timep)
+#undef gmtime
 {
   struct tm *tm = gmtime (timep);
 

lib/regexec.c

@@ -2783,8 +2783,11 @@ get_subexp (re_match_context_t *mctx, Idx bkref_node, Idx bkref_str_idx)
 	    return REG_ESPACE;
 	  err = get_subexp_sub (mctx, sub_top, sub_last, bkref_node,
 				bkref_str_idx);
+	  buf = (const char *) re_string_get_buffer (&mctx->input);
 	  if (err == REG_NOMATCH)
 	    continue;
+	  if (__glibc_unlikely (err != REG_NOERROR))
+	    return err;
 	}
     }
   return REG_NOERROR;

m4/regex.m4

@@ -1,4 +1,4 @@
-# serial 67
+# serial 68
 
 # Copyright (C) 1996-2001, 2003-2018 Free Software Foundation, Inc.
 #
@@ -213,6 +213,17 @@ AC_DEFUN([gl_REGEX],
             if (! REG_STARTEND)
               result |= 64;
 
+            /* Matching with the compiled form of this regexp would provoke
+               an assertion failure prior to glibc-2.28:
+                 regexec.c:1375: pop_fail_stack: Assertion 'num >= 0' failed
+               With glibc-2.28, compilation fails and reports the invalid
+               back reference.  */
+            re_set_syntax (RE_SYNTAX_POSIX_EGREP);
+            memset (&regex, 0, sizeof regex);
+            s = re_compile_pattern ("0|()0|\\1|0", 10, &regex);
+            if (!s || strcmp (s, "Invalid back reference"))
+              result |= 64;
+
 #if 0
             /* It would be nice to reject hosts whose regoff_t values are too
                narrow (including glibc on hosts with 64-bit ptrdiff_t and