bzr commit into mysql-5.0-bugteam branch (joro:2812) Bug#47106

[Georgi Kodinov]

#At file:///home/kgeorge/mysql/work/B47106-5.0-bugteam/ based on revid:sergey.glukhov@stripped

 2812 Georgi Kodinov	2009-09-18
      Bug #47106: Crash / segfault on adding EXPLAIN to a non-crashing
       query
            
      The fix for bug 46749 removed the check for OUTER_REF_TABLE_BIT 
      and substituted it for a check on the presence of 
      Item_ident::depended_from.
      Removing it altogether was wrong : OUTER_REF_TABLE_BIT should 
      still be checked in addition to depended_from (because it's not 
      set in all cases and doesn't contradict to the check of depended_from).
      Fixed by returning the old condition back as a compliment to the 
      new one.

    modified:
      mysql-test/r/subselect4.result
      mysql-test/t/subselect4.test
      sql/sql_select.cc
=== modified file 'mysql-test/r/subselect4.result'
--- a/mysql-test/r/subselect4.result	2009-09-03 15:03:46 +0000
+++ b/mysql-test/r/subselect4.result	2009-09-18 09:34:08 +0000
@@ -27,4 +27,35 @@ SELECT 1;
 1
 1
 DROP TABLE t1,t2,t3;
+#
+# Bug #47106: Crash / segfault on adding EXPLAIN to a non-crashing 
+# query
+#
+CREATE TABLE t1 (
+a INT,
+b INT,
+PRIMARY KEY (a),
+KEY b (b)
+);
+INSERT INTO t1 VALUES (1, 1), (2, 1);
+CREATE TABLE t2 LIKE t1;
+INSERT INTO t2 SELECT * FROM t1;
+CREATE TABLE t3 LIKE t1;
+INSERT INTO t3 SELECT * FROM t1;
+# Should not crash.
+# Should have 1 impossible where and 2 dependent subqs.
+EXPLAIN
+SELECT
+(SELECT 1 FROM t1,t2 WHERE t2.b > t3.b)
+FROM t3 WHERE 1 = 0 GROUP BY 1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
+2	DEPENDENT SUBQUERY	t1	index	NULL	PRIMARY	4	NULL	2	Using index
+2	DEPENDENT SUBQUERY	t2	index	b	b	5	NULL	2	Using where; Using index
+# should return 0 rows
+SELECT
+(SELECT 1 FROM t1,t2 WHERE t2.b > t3.b)
+FROM t3 WHERE 1 = 0 GROUP BY 1;
+(SELECT 1 FROM t1,t2 WHERE t2.b > t3.b)
+DROP TABLE t1,t2,t3;
 End of 5.0 tests.

=== modified file 'mysql-test/t/subselect4.test'
--- a/mysql-test/t/subselect4.test	2009-09-03 15:03:46 +0000
+++ b/mysql-test/t/subselect4.test	2009-09-18 09:34:08 +0000
@@ -28,5 +28,37 @@ SELECT 1;
 
 DROP TABLE t1,t2,t3;
 
+--echo #
+--echo # Bug #47106: Crash / segfault on adding EXPLAIN to a non-crashing 
+--echo # query
+--echo #
+
+CREATE TABLE t1 (
+  a INT,
+  b INT,
+  PRIMARY KEY (a),
+  KEY b (b)
+);
+INSERT INTO t1 VALUES (1, 1), (2, 1);
+
+CREATE TABLE t2 LIKE t1;
+INSERT INTO t2 SELECT * FROM t1;
+
+CREATE TABLE t3 LIKE t1;
+INSERT INTO t3 SELECT * FROM t1;
+
+--echo # Should not crash.
+--echo # Should have 1 impossible where and 2 dependent subqs.
+EXPLAIN
+SELECT
+  (SELECT 1 FROM t1,t2 WHERE t2.b > t3.b)
+FROM t3 WHERE 1 = 0 GROUP BY 1;
+
+--echo # should return 0 rows
+SELECT
+  (SELECT 1 FROM t1,t2 WHERE t2.b > t3.b)
+FROM t3 WHERE 1 = 0 GROUP BY 1;
+
+DROP TABLE t1,t2,t3;
 
 --echo End of 5.0 tests.

=== modified file 'sql/sql_select.cc'
--- a/sql/sql_select.cc	2009-09-03 15:03:46 +0000
+++ b/sql/sql_select.cc	2009-09-18 09:34:08 +0000
@@ -3216,12 +3216,12 @@ add_key_equal_fields(KEY_FIELD **key_fie
      @retval FALSE  it's something else
 */
 
-inline static bool
+static bool
 is_local_field (Item *field)
 {
-  field= field->real_item();
-  return field->type() == Item::FIELD_ITEM && 
-    !((Item_field *)field)->depended_from;
+  return field->real_item()->type() == Item::FIELD_ITEM
+    && !(field->used_tables() & OUTER_REF_TABLE_BIT)
+    && !((Item_field *)field->real_item())->depended_from;
 }
 
 


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