fnmatch.m4 patch to catch bug in older glibc

[Paul Eggert]

Now that gnulib has a patch for this older glibc bug (which is still
present in Debian stable) we should check for the bug.  I installed
this:

2007-01-24  Paul Eggert  <address@hidden>

        * m4/fnmatch.m4 (_AC_FUNC_FNMATCH_IF): Add test for glibc bug 361.
        Don't use 'exit'; just return from 'main'.

--- m4/fnmatch.m4       16 Jan 2007 16:31:23 -0000      1.27
+++ m4/fnmatch.m4       25 Jan 2007 00:39:39 -0000
@@ -23,33 +23,52 @@ AC_DEFUN([_AC_FUNC_FNMATCH_IF],
    dnl Thanks to John Oleynick, François Pinard, and Paul Eggert for this test.
    AC_RUN_IFELSE(
       [AC_LANG_PROGRAM(
-        [
-#         include <stdlib.h>
-#         include <fnmatch.h>
-#         define y(a, b, c) (fnmatch (a, b, c) == 0)
-#         define n(a, b, c) (fnmatch (a, b, c) == FNM_NOMATCH)
+        [[#include <fnmatch.h>
           static int
-          fnm (char const *pattern, char const *string, int flags)
+          y (char const *pattern, char const *string, int flags)
           {
-            return fnmatch (pattern, string, flags);
+            return fnmatch (pattern, string, flags) == 0;
           }
-        ],
-        [exit
-          (!(fnm ("a*", "", 0) == FNM_NOMATCH
+          static int
+          n (char const *pattern, char const *string, int flags)
+          {
+            return fnmatch (pattern, string, flags) == FNM_NOMATCH;
+          }
+        ]],
+        [[char const *Apat = 'A' < '\\\\' ? "[A-\\\\\\\\]" : "[\\\\\\\\-A]";
+          char const *apat = 'a' < '\\\\' ? "[a-\\\\\\\\]" : "[\\\\\\\\-a]";
+          static char const A_1[] = { 'A' - 1, 0 };
+          static char const A01[] = { 'A' + 1, 0 };
+          static char const a_1[] = { 'a' - 1, 0 };
+          static char const a01[] = { 'a' + 1, 0 };
+          static char const bs_1[] = { '\\\\' - 1, 0 };
+          static char const bs01[] = { '\\\\' + 1, 0 };
+          return
+           !(n ("a*", "", 0)
              && y ("a*", "abc", 0)
              && n ("d*/*1", "d/s/1", FNM_PATHNAME)
              && y ("a\\\\bc", "abc", 0)
              && n ("a\\\\bc", "abc", FNM_NOESCAPE)
              && y ("*x", ".x", 0)
              && n ("*x", ".x", FNM_PERIOD)
-             && m4_if([$1], [GNU],
+             && y (Apat, "\\\\", 0) && y (Apat, "A", 0)
+             && y (apat, "\\\\", 0) && y (apat, "a", 0)
+             && n (Apat, A_1, 0) == ('A' < '\\\\')
+             && n (apat, a_1, 0) == ('a' < '\\\\')
+             && y (Apat, A01, 0) == ('A' < '\\\\')
+             && y (apat, a01, 0) == ('a' < '\\\\')
+             && y (Apat, bs_1, 0) == ('A' < '\\\\')
+             && y (apat, bs_1, 0) == ('a' < '\\\\')
+             && n (Apat, bs01, 0) == ('A' < '\\\\')
+             && n (apat, bs01, 0) == ('a' < '\\\\')
+             && ]m4_if([$1], [GNU],
                   [y ("xxXX", "xXxX", FNM_CASEFOLD)
                    && y ("a++(x|yy)b", "a+xyyyyxb", FNM_EXTMATCH)
                    && n ("d*/*1", "d/s/1", FNM_FILE_NAME)
                    && y ("*", "x", FNM_FILE_NAME | FNM_LEADING_DIR)
                    && y ("x*", "x/y/z", FNM_FILE_NAME | FNM_LEADING_DIR)
                    && y ("*c*", "c/x", FNM_FILE_NAME | FNM_LEADING_DIR)],
-                  1)));])],
+                  1))[;]])],
       [$2=yes],
       [$2=no],
       [$2=cross])])