- Patch #100850 by webchick et al: log field in {node_revisions} table has no default value.

modules/node/node.module

@@ -588,7 +588,7 @@ function node_save(&$node) {
                      'title' => "'%s'", 'body' => "'%s'",
                      'teaser' => "'%s'", 'timestamp' => '%d',
                      'uid' => '%d', 'format' => '%d');
-  if (!empty($node->log)) {
+  if (!empty($node->log) || $node->is_new) {
     // Only store the log message if there's something to store; this prevents
     // existing log messages from being unintentionally overwritten by a blank
     // message. A new revision will have an empty log message (or $node->log).