Merged revisions 232268 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r232268 | dvossel | 2009-12-02 09:41:36 -0600 (Wed, 02 Dec 2009) | 9 lines
  
  fixes segfault in func_groupcount
  
  closes issue #16337)
  Reported by: Parantido
  Patches:
        issue_16337.diff uploaded by dvossel (license 671)
  	  Tested by: Parantido, dvossel
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@232269 65c4cc65-6c06-0410-ace0-fbb531ad65f3

funcs/func_groupcount.c

@@ -196,6 +196,10 @@ static int group_function_write(struct ast_channel *chan, const char *cmd,
 {
 	char grpcat[256];
 
+	if (!value) {
+		return -1;
+	}
+
 	if (!ast_strlen_zero(data)) {
 		snprintf(grpcat, sizeof(grpcat), "%s@%s", value, data);
 	} else {