Auto-merge from mysql-trunk.

sql/sql_class.h

@@ -1094,6 +1094,7 @@ public:
   bool enable_slow_log;
   bool last_insert_id_used;
   SAVEPOINT *savepoints;
+  enum enum_check_fields count_cuted_fields;
 };
 
 
@@ -1469,7 +1470,11 @@ struct Ha_data
     @sa trans_register_ha()
   */
   Ha_trx_info ha_info[2];
-
+  /**
+    NULL: engine is not bound to this thread
+    non-NULL: engine is bound to this thread, engine shutdown forbidden
+  */
+  plugin_ref lock;
   Ha_data() :ha_ptr(NULL) {}
 };
 
@@ -2046,8 +2051,15 @@ public:
   */
   ha_rows    sent_row_count;
 
-  /*
-    number of rows we read, sent or not, including in create_sort_index()
+  /**
+    Number of rows read and/or evaluated for a statement. Used for
+    slow log reporting.
+
+    An examined row is defined as a row that is read and/or evaluated
+    according to a statement condition, including in
+    create_sort_index(). Rows may be counted more than once, e.g., a
+    statement including ORDER BY could possibly evaluate the row in
+    filesort() before reading it for e.g. update.
   */
   ha_rows    examined_row_count;