WL#5370 Keep forward-compatibility when changing

        'CREATE TABLE IF NOT EXISTS ... SELECT' behaviour
BUG#47132, BUG#47442, BUG49494, BUG#23992 and BUG#48814 will disappear
automatically after the this patch.
BUG#55617 is fixed by this patch too.
            
This is the 5.5 part.
It implements:
- 'CREATE TABLE IF NOT EXISTS ... SELECT' statement will not insert
  anything and binlog anything if the table already exists.
  It only generate a warning that table already exists.
- A couple of test cases for the behavior changing.

1 files changed, 0 insertions, 17 deletions

diff --git a/sql/table.h b/sql/table.h
index 52ac92299a6..6ed3ec0a921 100644
--- a/sql/table.h
+++ b/sql/table.h
@@ -1587,23 +1587,6 @@ struct TABLE_LIST
     /* Don't associate a table share. */
     OPEN_STUB
   } open_strategy;
-  /**
-    Indicates the locking strategy for the object being opened.
-  */
-  enum
-  {
-    /*
-      Take metadata lock specified by 'mdl_request' member before
-      the object is opened. Do nothing after that.
-    */
-    OTLS_NONE= 0,
-    /*
-      Take (exclusive) metadata lock specified by 'mdl_request' member
-      before object is opened. If opening is successful, downgrade to
-      a shared lock.
-    */
-    OTLS_DOWNGRADE_IF_EXISTS
-  } lock_strategy;
   /* For transactional locking. */
   int           lock_timeout;           /* NOWAIT or WAIT [X]               */
   bool          lock_transactional;     /* If transactional lock requested. */