- Fixed a problem editing nodes.  Spotted by Steven.

modules/forum.module

@@ -214,7 +214,7 @@ function forum_validate(&$node) {
 }
 
 function forum_form(&$node, &$error) {
-  if (!$node->taxonomy) {
+  if (!$node->nid) {
     // new topic
     $node->taxonomy[] = arg(3);
   }

modules/forum/forum.module

@@ -214,7 +214,7 @@ function forum_validate(&$node) {
 }
 
 function forum_form(&$node, &$error) {
-  if (!$node->taxonomy) {
+  if (!$node->nid) {
     // new topic
     $node->taxonomy[] = arg(3);
   }