Index: modules/node/node.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/node/node.module,v
retrieving revision 1.967
diff -u -p -r1.967 node.module
--- modules/node/node.module	26 May 2008 17:12:55 -0000	1.967
+++ modules/node/node.module	28 May 2008 05:46:36 -0000
@@ -888,13 +888,10 @@ function node_save(&$node) {
   node_invoke_nodeapi($node, 'presave');
   global $user;
 
-  $node->is_new = FALSE;
-
-  // Apply filters to some default node fields:
-  if (empty($node->nid)) {
-    // Insert a new node.
-    $node->is_new = TRUE;
+  // Insert a new node.
+  $node->is_new = empty($node->nid);
 
+  if ($node->is_new || !empty($node->revision)) {
     // When inserting a node, $node->log must be set because
     // {node_revisions}.log does not (and cannot) have a default
     // value.  If the user does not have permission to create
@@ -903,25 +900,26 @@ function node_save(&$node) {
     if (!isset($node->log)) {
       $node->log = '';
     }
+  }
+  elseif (empty($node->log)) {
+    // When updating a node, however, avoid clobbering an existing
+    // log entry with an empty one.
+    unset($node->log);
+  }
 
-    // For the same reasons, make sure we have $node->teaser and
-    // $node->body.  We should consider making these fields nullable
-    // in a future version since node types are not required to use them.
-    if (!isset($node->teaser)) {
-      $node->teaser = '';
-    }
-    if (!isset($node->body)) {
-      $node->body = '';
-    }
+  // For the same reasons, make sure we have $node->teaser and
+  // $node->body.  We should consider making these fields nullable
+  // in a future version since node types are not required to use them.
+  if (!isset($node->teaser)) {
+    $node->teaser = '';
   }
-  elseif (!empty($node->revision)) {
-    $node->old_vid = $node->vid;
+  if (!isset($node->body)) {
+    $node->body = '';
   }
-  else {
-    // When updating a node, avoid clobberring an existing log entry with an empty one.
-    if (empty($node->log)) {
-      unset($node->log);
-    }
+
+  // Save the old revision if needed.
+  if (!$node->is_new && !empty($node->revision) && $node->vid) {
+    $node->old_vid = $node->vid;
   }
 
   // Set some required fields: