sql_load.cc:

  Added a comment for already pushed bug fix

sql/sql_load.cc

@@ -93,6 +93,11 @@ int mysql_load(THD *thd,sql_exchange *ex,TABLE_LIST *table_list,
   char *db = table_list->db;			// This is never null
   /* If no current database, use database where table is located */
   char *tdb= thd->db ? thd->db : db;
+  /*
+    'tdb' can be NULL only if both table_list->db and thd->db are NULL
+    'db' itself can be NULL.  but in that  case it   will generate 
+    an error earlier open_ltable()).
+  */
   bool transactional_table, log_delayed;
   ulong skip_lines= ex->skip_lines;
   DBUG_ENTER("mysql_load");