merge

mysql-test/r/subselect.result:
  Auto merged
mysql-test/t/subselect.test:
  Auto merged
sql/item.cc:
  Auto merged
sql/item.h:
  Auto merged
sql/item_cmpfunc.cc:
  Auto merged
sql/item_cmpfunc.h:
  Auto merged
sql/item_func.cc:
  Auto merged
sql/item_func.h:
  Auto merged
sql/mysql_priv.h:
  Auto merged
sql/mysqld.cc:
  Auto merged
sql/sql_delete.cc:
  Auto merged
sql/sql_lex.cc:
  Auto merged
sql/sql_lex.h:
  Auto merged
sql/sql_parse.cc:
  Auto merged
sql/sql_select.cc:
  Auto merged
sql/sql_table.cc:
  Auto merged
sql/sql_update.cc:
  Auto merged
sql/sql_yacc.yy:
  Auto merged
sql/table.h:
  Auto merged

1 files changed, 12 insertions, 2 deletions

diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index f33533d9eb7..dc6e791c4be 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -1355,6 +1355,7 @@ int open_tables(THD *thd,TABLE_LIST *start)
   int result=0;
   DBUG_ENTER("open_tables");
 
+  thd->current_tablenr= 0;
  restart:
   thd->proc_info="Opening tables";
   for (tables=start ; tables ; tables=tables->next)
@@ -1473,6 +1474,7 @@ TABLE *open_ltable(THD *thd, TABLE_LIST *table_list, thr_lock_type lock_type)
   DBUG_ENTER("open_ltable");
 
   thd->proc_info="Opening table";
+  thd->current_tablenr= 0;
   while (!(table=open_table(thd,table_list->db,
 			    table_list->real_name,table_list->alias,
 			    &refresh)) && refresh) ;
@@ -2141,6 +2143,7 @@ insert_fields(THD *thd,TABLE_LIST *tables, const char *db_name,
 
 int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
 {
+  table_map not_null_tables= 0;
   DBUG_ENTER("setup_conds");
   thd->set_query_id=1;
   
@@ -2150,6 +2153,7 @@ int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
     thd->where="where clause";
     if ((*conds)->fix_fields(thd, tables, conds) || (*conds)->check_cols(1))
       DBUG_RETURN(1);
+    not_null_tables= (*conds)->not_null_tables();
   }
 
   /* Check if we are using outer joins */
@@ -2164,9 +2168,15 @@ int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
 	DBUG_RETURN(1);
       thd->lex.current_select->cond_count++;
 
-      /* If it's a normal join, add the ON/USING expression to the WHERE */
-      if (!table->outer_join)
+      /*
+	If it's a normal join or a LEFT JOIN which can be optimized away
+	add the ON/USING expression to the WHERE
+      */
+      if (!table->outer_join ||
+	  ((table->table->map & not_null_tables) &&
+	   !(specialflag & SPECIAL_NO_NEW_FUNC)))
       {
+	table->outer_join= 0;
 	if (!(*conds=and_conds(*conds, table->on_expr)))
 	  DBUG_RETURN(1);
 	table->on_expr=0;