regex.m4: correct the reversed range endpoint ([b-a]) test

[gnulib.git] / m4 / regex.m4

diff --git a/m4/regex.m4 b/m4/regex.m4
index 6bd6b8f..95784e4 100644 (file)
--- a/m4/regex.m4
+++ b/m4/regex.m4
@@ -1,4 +1,4 @@
-# serial 55
+# serial 56
 
 # Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2006,
 # 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
@@ -96,8 +96,9 @@ AC_DEFUN([gl_REGEX],
             if (!s)
               return 1;
 
-            /* Ensure that [b-a] is diagnosed as invalid. */
-            re_set_syntax (RE_SYNTAX_POSIX_EGREP);
+            /* Ensure that [b-a] is diagnosed as invalid, when
+               using RE_NO_EMPTY_RANGES. */
+            re_set_syntax (RE_SYNTAX_POSIX_EGREP | RE_NO_EMPTY_RANGES);
             memset (&regex, 0, sizeof regex);
             s = re_compile_pattern ("a[b-a]", 6, &regex);
             if (s == 0)