ensure that the regexp [b-a] is diagnosed as invalid

* m4/regex.m4 (gl_REGEX): Ensure that re_compiler_pattern
diagnoses [b-a] as invalid when using RE_SYNTAX_POSIX_EGREP.
Currently, glibc-2.11.90-10 fails to do that.

diff --git a/m4/regex.m4 b/m4/regex.m4
index a70225247f4fbade017921b5357d34d4edaf3313..6bd6b8f7d4e6218874d715bf7041b9aa91cbdca6 100644 (file)
--- a/m4/regex.m4
+++ b/m4/regex.m4
@@ -96,6 +96,13 @@ AC_DEFUN([gl_REGEX],
             if (!s)
               return 1;
 
+            /* Ensure that [b-a] is diagnosed as invalid. */
+            re_set_syntax (RE_SYNTAX_POSIX_EGREP);
+            memset (&regex, 0, sizeof regex);
+            s = re_compile_pattern ("a[b-a]", 6, &regex);
+            if (s == 0)
+              return 1;
+
             /* This should succeed, but does not for glibc-2.1.3.  */
             memset (&regex, 0, sizeof regex);
             s = re_compile_pattern ("{1", 2, &regex);