Fixed LP bug #874378.

This bug happened for the queries over multi-table mergeable views
because the bitmap TABLE::read_set of the underlying tables were not
updated after the views had been merged into the query.
Now this bitmaps are updated properly.
Also the bitmap TABLE::merge_keys now is updated in prevention of
future bugs.

mysql-test/r/derived_view.result

@@ -1576,4 +1576,59 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	3	Using temporary; Using filesort
 DROP VIEW v1,v2;
 DROP TABLE t1,t2;
+#
+# Bug #743378: join over merged view employing BNL
+#
+CREATE TABLE t1 ( d varchar(1) NOT NULL) ;
+INSERT INTO t1 VALUES ('j'),('v'),('c');
+CREATE TABLE t2 (h time NOT NULL, d varchar(1) NOT NULL) ;
+INSERT INTO t2 VALUES ('05:03:03','w'),('02:59:24','d'),('00:01:58','e');
+CREATE TABLE t3 (
+b int NOT NULL, e varchar(1) NOT NULL, d varchar(1) NOT NULL, KEY (e,b)
+);
+INSERT INTO t3 VALUES (4,'x','x'),(9,'w','w'),(4,'d','d'),(8,'e','e');
+CREATE TABLE t4 (i int NOT NULL, m varchar(1) NOT NULL) ;
+INSERT INTO t4 VALUES (8,'m'),(9,'d'),(2,'s'),(4,'r'),(8,'m');
+CREATE TABLE t5 (
+a int NOT NULL, c int NOT NULL, b int NOT NULL, f date NOT NULL,
+g date NOT NULL, h time NOT NULL, j time NOT NULL, k datetime NOT NULL
+);
+INSERT INTO t5 VALUES
+(1,4,0,'0000-00-00','0000-00-00','21:22:34','21:22:34','2002-02-13 17:30'),
+(2,6,8,'2004-09-18','2004-09-18','10:50:38','10:50:38','2008-09-27 00:34');
+CREATE VIEW v3 AS SELECT t3.*, t4.i FROM t3, t4, t5;
+SET SESSION join_cache_level = 1;
+SET SESSION join_buffer_size = 512;
+EXPLAIN
+SELECT t2.d FROM t1,t2,v3 WHERE v3.e = t2.d AND v3.i < 3;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	
+1	SIMPLE	t3	ref	e	e	3	test.t2.d	1	Using index
+1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using join buffer (flat, BNL join)
+1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
+SELECT t2.d FROM t1,t2,v3 WHERE v3.e = t2.d AND v3.i < 3;
+d
+w
+d
+e
+w
+d
+e
+w
+d
+e
+w
+d
+e
+w
+d
+e
+w
+d
+e
+SET SESSION join_cache_level = DEFAULT;
+SET SESSION join_buffer_size = DEFAULT;
+DROP VIEW v3;
+DROP TABLE t1,t2,t3,t4,t5;
 set optimizer_switch=@exit_optimizer_switch;

mysql-test/t/derived_view.test

@@ -1016,5 +1016,48 @@ SELECT v1.a FROM v1,v2 WHERE v2.b = v1.b ORDER BY 1;
 DROP VIEW v1,v2;
 DROP TABLE t1,t2;
 
+
+--echo #
+--echo # Bug #743378: join over merged view employing BNL
+--echo #
+
+CREATE TABLE t1 ( d varchar(1) NOT NULL) ;
+INSERT INTO t1 VALUES ('j'),('v'),('c');
+
+CREATE TABLE t2 (h time NOT NULL, d varchar(1) NOT NULL) ;
+INSERT INTO t2 VALUES ('05:03:03','w'),('02:59:24','d'),('00:01:58','e');
+
+CREATE TABLE t3 (
+  b int NOT NULL, e varchar(1) NOT NULL, d varchar(1) NOT NULL, KEY (e,b)
+);
+INSERT INTO t3 VALUES (4,'x','x'),(9,'w','w'),(4,'d','d'),(8,'e','e');
+
+CREATE TABLE t4 (i int NOT NULL, m varchar(1) NOT NULL) ;
+INSERT INTO t4 VALUES (8,'m'),(9,'d'),(2,'s'),(4,'r'),(8,'m');
+
+CREATE TABLE t5 (
+  a int NOT NULL, c int NOT NULL, b int NOT NULL, f date NOT NULL,
+  g date NOT NULL, h time NOT NULL, j time NOT NULL, k datetime NOT NULL
+);
+
+INSERT INTO t5 VALUES
+  (1,4,0,'0000-00-00','0000-00-00','21:22:34','21:22:34','2002-02-13 17:30'),
+  (2,6,8,'2004-09-18','2004-09-18','10:50:38','10:50:38','2008-09-27 00:34');
+
+CREATE VIEW v3 AS SELECT t3.*, t4.i FROM t3, t4, t5;
+
+SET SESSION join_cache_level = 1;
+SET SESSION join_buffer_size = 512;
+
+EXPLAIN
+SELECT t2.d FROM t1,t2,v3 WHERE v3.e = t2.d AND v3.i < 3;
+SELECT t2.d FROM t1,t2,v3 WHERE v3.e = t2.d AND v3.i < 3;
+
+SET SESSION join_cache_level = DEFAULT;
+SET SESSION join_buffer_size = DEFAULT;
+
+DROP VIEW v3;
+DROP TABLE t1,t2,t3,t4,t5;
+
 # The following command must be the last one the file 
 set optimizer_switch=@exit_optimizer_switch;

sql/item.cc

@@ -2172,10 +2172,9 @@ bool Item_field::enumerate_field_refs_processor(uchar *arg)
   return FALSE;
 }
 
-bool Item_field::covering_keys_processor(uchar *arg)
+bool Item_field::update_table_bitmaps_processor(uchar *arg)
 {
-  if (field && field->table)
-    field->table->covering_keys.intersect(field->part_of_key);
+  update_table_bitmaps();
   return FALSE;
 }
 

sql/item.h

@@ -1018,7 +1018,7 @@ public:
   virtual bool mark_as_eliminated_processor(uchar *arg) { return 0; }
   virtual bool eliminate_subselect_processor(uchar *arg) { return 0; }
   virtual bool set_fake_select_as_master_processor(uchar *arg) { return 0; }
-  virtual bool covering_keys_processor(uchar *arg) { return 0; }
+  virtual bool update_table_bitmaps_processor(uchar *arg) { return 0; }
   virtual bool view_used_tables_processor(uchar *arg) { return 0; }
   virtual bool eval_not_null_tables(uchar *opt_arg) { return 0; }
   virtual bool clear_sum_processor(uchar *opt_arg) { return 0; }
@@ -1817,11 +1817,20 @@ public:
   bool get_date_result(MYSQL_TIME *ltime,uint fuzzydate);
   bool is_null() { return field->is_null(); }
   void update_null_value();
-  void update_used_tables() 
+  void update_table_bitmaps()
   {
     if (field && field->table)
-      field->table->covering_keys.intersect(field->part_of_key);
-  }
+    {
+      TABLE *tab= field->table;
+      tab->covering_keys.intersect(field->part_of_key);
+      tab->merge_keys.merge(field->part_of_key);
+      if (tab->read_set)
+        bitmap_fast_test_and_set(tab->read_set, field->field_index);
+      if (field->vcol_info)
+        tab->mark_virtual_col(field);
+    }  
+  }
+  void update_used_tables() { update_table_bitmaps(); }
   Item *get_tmp_table_item(THD *thd);
   bool collect_item_field_processor(uchar * arg);
   bool add_field_to_set_processor(uchar * arg);
@@ -1833,7 +1842,7 @@ public:
   bool vcol_in_partition_func_processor(uchar *bool_arg);
   bool check_vcol_func_processor(uchar *arg) { return FALSE;}
   bool enumerate_field_refs_processor(uchar *arg);
-  bool covering_keys_processor(uchar *arg);
+  bool update_table_bitmaps_processor(uchar *arg);
   void cleanup();
   Item_equal *get_item_equal() { return item_equal; }
   void set_item_equal(Item_equal *item_eq) { item_equal= item_eq; }

sql/item_subselect.cc

@@ -492,7 +492,7 @@ void Item_subselect::recalc_used_tables(st_select_lex *new_parent,
           upper->item->walk(&Item::enumerate_field_refs_processor, FALSE,
                             (uchar*)&fixer);
           used_tables_cache |= fixer.used_tables;
-          upper->item->walk(&Item::covering_keys_processor, FALSE, NULL);
+          upper->item->walk(&Item::update_table_bitmaps_processor, FALSE, NULL);
 /*
           if (after_pullout)
             upper->item->fix_after_pullout(new_parent, &(upper->item));

sql/sql_lex.cc

@@ -3411,7 +3411,7 @@ void SELECT_LEX::update_used_tables()
   while ((tl= ti++))
   {
     TABLE_LIST *embedding;
-    if (tl->table)
+    if (tl->table && !tl->is_view_or_derived())
     {
       embedding= tl->embedding;
       for (embedding= tl->embedding; embedding; embedding=embedding->embedding)
@@ -3422,6 +3422,9 @@ void SELECT_LEX::update_used_tables()
           TABLE *tab= tl->table;
           tab->covering_keys= tab->s->keys_for_keyread;
           tab->covering_keys.intersect(tab->keys_in_use_for_query);
+          tab->merge_keys.clear_all();
+          bitmap_clear_all(tab->read_set);
+          bitmap_clear_all(tab->vcol_set);
           break;
         }
       }