bzr push into mysql-5.5-cluster-7.2 branch (ole.john.aske:3909 to 3910)

[Ole John Aske]

 3910 Ole John Aske	2012-05-04
      Fixed Valgrind 'ininitialized memory read' errors caused by previous commit (revno: 3909)
      
      Checking for lock_mode inside ::table_flags() may read uninitialized data, and 
      was not particularly usefull either as part of setting the 'CONST_BLOCK' flag.
      So it has been deemed obsolete and removed in this fix.

    modified:
      sql/ha_ndbcluster.cc
 3909 Ole John Aske	2012-05-03
      ha_ndbcluster::read_first_row() was once implemented as part of the SPJ project
      as we then had plans for pushing queries with 'system' tables as root operation.
      (JT_SYSTEM is the only use case for ::read_first_row())
      
      It was later decided that we should not push such queries, but
      ha_ndbcluster::read_first_row() has remained in the code since then.
      
      There is a default implementation of this method (handler::read_first_row()) which
      is almost identical, except that it does not call ha_rnd_end() / ha_index_end()
      before returning. These calls was removed in our ha_ndbcluster::read_first_row()
      as pushed joins required the resultset to stay 'open' due to the child operations.
      
      However:
       - We do not push queries with 'system' tables so such a change
         is not required.
       - As part of fixing bug#13901890 'SQL NODE CRASHES DURING INSERT SELECT'
         we identified part of the root cause to be an overridden
         ::index_read_idx_map() which also omitted calling rnd_end()/index_end()
         before returning.
      
      This fix removes this obsolete, and potential evil code.

    modified:
      sql/ha_ndbcluster.cc
      sql/ha_ndbcluster.h
=== modified file 'sql/ha_ndbcluster.cc'
--- a/sql/ha_ndbcluster.cc	2012-05-03 12:12:39 +0000
+++ b/sql/ha_ndbcluster.cc	2012-05-04 08:17:44 +0000
@@ -12442,16 +12442,11 @@ ulonglong ha_ndbcluster::table_flags(voi
     f= (f | HA_BINLOG_STMT_CAPABLE) & ~HA_HAS_OWN_BINLOGGING;
 
   /**
-   * To maximize join pushability we want const-table optimization
-   * blocked if table is possibly pushable, that is:
-   *  - Variable 'ndb_join_pushdown= on'
-   *  - Lock mode is LM_CommittedRead
+   * To maximize join pushability we want const-table 
+   * optimization blocked if 'ndb_join_pushdown= on'
    */
-  if (THDVAR(thd, join_pushdown) &&
-      get_ndb_lock_mode(m_lock.type) == NdbOperation::LM_CommittedRead)
-  {
+  if (THDVAR(thd, join_pushdown))
     f= f | HA_BLOCK_CONST_TABLE;
-  }
 
   return f;
 }

No bundle (reason: useless for push emails).