Detect invalid hostgroup expressions

Author: ferki

ChangeLog

@@ -4,6 +4,7 @@ Revision history for Rex
  [API CHANGES]
 
  [BUG FIXES]
+ - Detect invalid hostgroup expressions
 
  [DOCUMENTATION]
 

lib/Rex/Commands.pm

@@ -1786,9 +1786,12 @@ sub evaluate_hostname {
   if ( $rule =~ m/,/ ) {
     @ret = _evaluate_hostname_list( $start, $rule, $end );
   }
-  else {
+  elsif ( $rule =~ m/[.]{2}/msx ) {
     @ret = _evaluate_hostname_range( $start, $rule, $end );
   }
+  else {
+    croak('Invalid hostgroup expression');
+  }
 
   return @ret;
 }