The isnumber() function now checks the given pointer for NULL

CONTRIBUTORS

@@ -2727,3 +2727,6 @@ Johan Andersson <jna@jna.pp.se>
 Dave Pickles <dave@pickles.me.uk>
  for adding support for "content identifier descriptor" and "default authority
  descriptor" to 'libsi'
+
+Holger Dengler <holger.dengler@gmx.de>
+ for making the isnumber() function check the given pointer for NULL

HISTORY

@@ -6650,6 +6650,8 @@ Video Disk Recorder Revision History
 - Added support for "content identifier descriptor" and "default authority descriptor"
   to 'libsi' (thanks to Dave Pickles).
 
-2011-06-21: Version 1.7.20
+2011-07-31: Version 1.7.20
 
 - Added some missing 'const' to tChannelID (reported by Sundararaj Reel).
+- The isnumber() function now checks the given pointer for NULL (thanks to Holger
+  Dengler).

tools.c

@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: tools.c 2.14 2011/04/29 14:51:14 kls Exp $
+ * $Id: tools.c 2.15 2011/07/31 13:19:28 kls Exp $
  */
 
 #include "tools.h"
@@ -261,7 +261,7 @@ int numdigits(int n)
 
 bool isnumber(const char *s)
 {
-  if (!*s)
+  if (!s || !*s)
      return false;
   do {
      if (!isdigit(*s))