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[Sergey Petrunia <psergey@xxxxxxxxxxxx>]

#At lp:maria based on revid:psergey@xxxxxxxxxxxx-20090614123504-jf4pcb333ojwaxfy

 2714 Sergey Petrunia	2009-06-15
      MWL#17: Table elimination
      - Fix print_join() to work both for EXPLAIN EXTENDED (after table elimination) and for 
        CREATE VIEW (after join->prepare() but without any optimization).
      modified:
        mysql-test/r/union.result
        sql/sql_select.cc

per-file messages:
  mysql-test/r/union.result
    MWL#17: Table elimination
    - Adjust test results
  sql/sql_select.cc
    MWL#17: Table elimination
    - Fix print_join() to work both for EXPLAIN EXTENDED (after table elimination) and for 
      CREATE VIEW (after join->prepare() but without any optimization).
=== modified file 'mysql-test/r/union.result'
--- a/mysql-test/r/union.result	2009-03-19 10:18:52 +0000
+++ b/mysql-test/r/union.result	2009-06-14 20:59:24 +0000
@@ -522,7 +522,7 @@ id	select_type	table	type	possible_keys	
 2	UNION	t2	const	PRIMARY	PRIMARY	4	const	1	100.00	
 NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	(select '1' AS `a`,'1' AS `b` from `test`.`t1` where ('1' = 1)) union (select '1' AS `a`,'10' AS `b` from `test`.`t2` where ('1' = 1))
+Note	1003	(select '1' AS `a`,'1' AS `b` from `test`.`t1` where 1) union (select '1' AS `a`,'10' AS `b` from `test`.`t2` where 1)
 (select * from t1 where a=5) union (select * from t2 where a=1);
 a	b
 1	10

=== modified file 'sql/sql_select.cc'
--- a/sql/sql_select.cc	2009-06-14 12:35:04 +0000
+++ b/sql/sql_select.cc	2009-06-14 20:59:24 +0000
@@ -16937,18 +16937,28 @@ static void print_join(THD *thd,
     *t= ti++;
 
   DBUG_ASSERT(tables->elements >= 1);
-  //pserey:TODO check!
+  /*
+    Assert that the first table in the list isn't eliminated (if it was we
+    would have skipped the entire join nest)
+  */
+  DBUG_ASSERT(!eliminated_tables || 
+              !((*table)->table && ((*table)->table->map & eliminated_tables) ||
+                (*table)->nested_join && !((*table)->nested_join->used_tables &
+                                       ~eliminated_tables)));
   (*table)->print(thd, eliminated_tables, str, query_type);
 
   TABLE_LIST **end= table + tables->elements;
   for (TABLE_LIST **tbl= table + 1; tbl < end; tbl++)
   {
     TABLE_LIST *curr= *tbl;
-    // psergey-todo-todo: 
-    //  base table: check 
-    if (curr->table && (curr->table->map & eliminated_tables) ||
-        curr->nested_join && !(curr->nested_join->used_tables &
-                               ~eliminated_tables))
+    /*
+       The (*) check guards againist the case of printing the query for
+       CREATE VIEW. There we'll have nested_join->used_tables==0.
+    */
+    if (eliminated_tables &&  // (*)
+        (curr->table && (curr->table->map & eliminated_tables) ||
+         curr->nested_join && !(curr->nested_join->used_tables &
+                                ~eliminated_tables)))
     {
       continue;
     }