From: Date: April 25 2007 3:05pm
Subject: bk commit into 5.0 tree (gkodinov:1.2440) BUG#27807
List-Archive: http://lists.mysql.com/commits/25401
X-Bug: 27807
Message-Id: <200704251305.l3PD5Fx4027494@magare.gmz>

Below is the list of changes that have just been committed into a local
5.0 repository of kgeorge. When kgeorge does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
For information on how to access the public repository
see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2007-04-25 16:05:09+03:00, gkodinov@stripped +3 -0
  Bug #27807:
  When creating the temp table structure to
  materialize a scalar subquery one of its 
  members is not set. This causes GPF
  in EXPLAIN.
  Fixed by seting the pos_in_table_list to 
  empty and displaying the proper text in
  select_describe().

  mysql-test/r/subselect.result@stripped, 2007-04-25 16:05:08+03:00, gkodinov@stripped +8 -0
    Bug #27807: test case

  mysql-test/t/subselect.test@stripped, 2007-04-25 16:05:08+03:00, gkodinov@stripped +9 -0
    Bug #27807: test case

  sql/sql_select.cc@stripped, 2007-04-25 16:05:08+03:00, gkodinov@stripped +12 -1
    Bug #27807: 
     - set pos_in_table_list for temp tables
     - displayed tables without pos_in_table_list

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	gkodinov
# Host:	magare.gmz
# Root:	/home/kgeorge/mysql/work/B27807-5.0-opt

--- 1.511/sql/sql_select.cc	2007-04-21 19:27:34 +03:00
+++ 1.512/sql/sql_select.cc	2007-04-25 16:05:08 +03:00
@@ -9228,6 +9228,7 @@ create_tmp_table(THD *thd,TMP_TABLE_PARA
   table->quick_keys.init();
   table->used_keys.init();
   table->keys_in_use_for_query.init();
+  table->pos_in_table_list= NULL;
 
   table->s= &table->share_not_to_be_used;
   table->s->blob_field= blob_field;
@@ -14968,9 +14969,19 @@ static void select_describe(JOIN *join, 
 			     table->derived_select_number);
 	item_list.push_back(new Item_string(table_name_buffer, len, cs));
       }
+      else if (!table->pos_in_table_list)
+      {
+        /* 
+          Table without TABLE_LIST. 
+          Usually a temp table result of scalar subquery materialization.
+        */
+        DBUG_ASSERT (table->s->tmp_table);
+        item_list.push_back(new Item_string("<temp_table>", 
+                                            sizeof ("<temp_table>") - 1, cs));
+      }
       else
       {
-        TABLE_LIST *real_table= table->pos_in_table_list; 
+        TABLE_LIST *real_table= table->pos_in_table_list;
 	item_list.push_back(new Item_string(real_table->alias,
 					    strlen(real_table->alias),
 					    cs));

--- 1.185/mysql-test/r/subselect.result	2007-04-20 13:26:57 +03:00
+++ 1.186/mysql-test/r/subselect.result	2007-04-25 16:05:08 +03:00
@@ -4012,3 +4012,11 @@ WHERE (SELECT COUNT(t0.b) FROM t1 t WHER
 ERROR HY000: Invalid use of group function
 SET @@sql_mode=default;
 DROP TABLE t1;
+CREATE TABLE t1 (a int, b int, KEY (a));
+INSERT INTO t1 VALUES (1,1),(2,1);
+EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ref	a	a	5	const	1	Using where; Using index
+2	SUBQUERY	<temp_table>	ALL	group_key	NULL	NULL	NULL	2	Using where
+DROP TABLE t1;
+End of 5.0 tests.

--- 1.149/mysql-test/t/subselect.test	2007-04-15 08:22:35 +03:00
+++ 1.150/mysql-test/t/subselect.test	2007-04-25 16:05:08 +03:00
@@ -2845,3 +2845,12 @@ SELECT a FROM t1 t0
 SET @@sql_mode=default;
 
 DROP TABLE t1;
+
+#
+# Bug #27807: Server crash when executing subquery with EXPLAIN
+#  
+CREATE TABLE t1 (a int, b int, KEY (a)); INSERT INTO t1 VALUES (1,1),(2,1);
+EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
+DROP TABLE t1;
+
+--echo End of 5.0 tests.