gnulib: Add module strverscmp.

* lib/strverscmp.c, m4/strverscmp.m4: New files.
* lib/Makefile.am, m4/gnulib-cache.m4, m4/gnulib-comp.m4: Update.

lib/Makefile.am

@@ -21,7 +21,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=tools --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files argmatch argp error gethrxtime isatty mkstemp mkstemps progname stpcpy sys_wait
+# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=tools --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files argmatch argp error gethrxtime isatty mkstemp mkstemps progname stpcpy strverscmp sys_wait
 
 AUTOMAKE_OPTIONS = 1.9.6 gnits
 
@@ -1253,6 +1253,15 @@ EXTRA_libgnu_la_SOURCES += strnlen.c
 
 ## end   gnulib module strnlen
 
+## begin gnulib module strverscmp
+
+
+EXTRA_DIST += strverscmp.c
+
+EXTRA_libgnu_la_SOURCES += strverscmp.c
+
+## end   gnulib module strverscmp
+
 ## begin gnulib module sys_stat
 
 BUILT_SOURCES += sys/stat.h

lib/strverscmp.c

@@ -0,0 +1,131 @@
+/* Compare strings while treating digits characters numerically.
+   Copyright (C) 1997, 2000, 2002, 2004, 2006, 2009-2013 Free Software
+   Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jean-François Bignolles <bignolle@ecoledoc.ibp.fr>, 1997.
+
+   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, 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/>.  */
+
+#if !_LIBC
+# include <config.h>
+#endif
+
+#include <string.h>
+#include <ctype.h>
+
+/* states: S_N: normal, S_I: comparing integral part, S_F: comparing
+           fractional parts, S_Z: idem but with leading Zeroes only */
+#define S_N    0x0
+#define S_I    0x4
+#define S_F    0x8
+#define S_Z    0xC
+
+/* result_type: CMP: return diff; LEN: compare using len_diff/diff */
+#define CMP    2
+#define LEN    3
+
+
+/* ISDIGIT differs from isdigit, as follows:
+   - Its arg may be any int or unsigned int; it need not be an unsigned char
+     or EOF.
+   - It's typically faster.
+   POSIX says that only '0' through '9' are digits.  Prefer ISDIGIT to
+   isdigit unless it's important to use the locale's definition
+   of "digit" even when the host does not conform to POSIX.  */
+#define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)
+
+#undef __strverscmp
+#undef strverscmp
+
+#ifndef weak_alias
+# define __strverscmp strverscmp
+#endif
+
+/* Compare S1 and S2 as strings holding indices/version numbers,
+   returning less than, equal to or greater than zero if S1 is less than,
+   equal to or greater than S2 (for more info, see the texinfo doc).
+*/
+
+int
+__strverscmp (const char *s1, const char *s2)
+{
+  const unsigned char *p1 = (const unsigned char *) s1;
+  const unsigned char *p2 = (const unsigned char *) s2;
+  unsigned char c1, c2;
+  int state;
+  int diff;
+
+  /* Symbol(s)    0       [1-9]   others  (padding)
+     Transition   (10) 0  (01) d  (00) x  (11) -   */
+  static const unsigned int next_state[] =
+  {
+      /* state    x    d    0    - */
+      /* S_N */  S_N, S_I, S_Z, S_N,
+      /* S_I */  S_N, S_I, S_I, S_I,
+      /* S_F */  S_N, S_F, S_F, S_F,
+      /* S_Z */  S_N, S_F, S_Z, S_Z
+  };
+
+  static const int result_type[] =
+  {
+      /* state   x/x  x/d  x/0  x/-  d/x  d/d  d/0  d/-
+                 0/x  0/d  0/0  0/-  -/x  -/d  -/0  -/- */
+
+      /* S_N */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
+                 CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
+      /* S_I */  CMP, -1,  -1,  CMP,  1,  LEN, LEN, CMP,
+                  1,  LEN, LEN, CMP, CMP, CMP, CMP, CMP,
+      /* S_F */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
+                 CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
+      /* S_Z */  CMP,  1,   1,  CMP, -1,  CMP, CMP, CMP,
+                 -1,  CMP, CMP, CMP
+  };
+
+  if (p1 == p2)
+    return 0;
+
+  c1 = *p1++;
+  c2 = *p2++;
+  /* Hint: '0' is a digit too.  */
+  state = S_N | ((c1 == '0') + (ISDIGIT (c1) != 0));
+
+  while ((diff = c1 - c2) == 0 && c1 != '\0')
+    {
+      state = next_state[state];
+      c1 = *p1++;
+      c2 = *p2++;
+      state |= (c1 == '0') + (ISDIGIT (c1) != 0);
+    }
+
+  state = result_type[state << 2 | ((c2 == '0') + (ISDIGIT (c2) != 0))];
+
+  switch (state)
+    {
+    case CMP:
+      return diff;
+
+    case LEN:
+      while (ISDIGIT (*p1++))
+        if (!ISDIGIT (*p2++))
+          return 1;
+
+      return ISDIGIT (*p2) ? -1 : diff;
+
+    default:
+      return state;
+    }
+}
+#ifdef weak_alias
+weak_alias (__strverscmp, strverscmp)
+#endif