automerge

mysql-test/r/subselect.result

@@ -4383,6 +4383,34 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	C	ALL	NULL	NULL	NULL	NULL	20	100.00	Using where
 DROP TABLE C;
 # End of test for bug#45061.
+#
+# Bug #46749: Segfault in add_key_fields() with outer subquery level 
+#   field references
+#
+CREATE TABLE t1 (
+a int,
+b int,
+UNIQUE (a), KEY (b)
+);
+INSERT INTO t1 VALUES (1,1), (2,1);
+CREATE TABLE st1 like t1;
+INSERT INTO st1 VALUES (1,1), (2,1);
+CREATE TABLE st2 like t1;
+INSERT INTO st2 VALUES (1,1), (2,1);
+EXPLAIN
+SELECT MAX(b), (SELECT COUNT(*) FROM st1,st2 WHERE st2.b <= t1.b)
+FROM t1 
+WHERE a = 230;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+2	DEPENDENT SUBQUERY	st1	index	NULL	a	5	NULL	2	Using index
+2	DEPENDENT SUBQUERY	st2	index	b	b	5	NULL	2	Using where; Using index; Using join buffer
+SELECT MAX(b), (SELECT COUNT(*) FROM st1,st2 WHERE st2.b <= t1.b)
+FROM t1 
+WHERE a = 230;
+MAX(b)	(SELECT COUNT(*) FROM st1,st2 WHERE st2.b <= t1.b)
+NULL	0
+DROP TABLE t1, st1, st2;
 End of 5.0 tests.
 CREATE TABLE t1 (a INT, b INT);
 INSERT INTO t1 VALUES (2,22),(1,11),(2,22);

mysql-test/t/subselect.test

@@ -3336,6 +3336,38 @@ EXPLAIN EXTENDED SELECT * FROM C WHERE `int_key` IN (SELECT `int_nokey`);
 DROP TABLE C;
 --echo # End of test for bug#45061.
 
+
+--echo #
+--echo # Bug #46749: Segfault in add_key_fields() with outer subquery level 
+--echo #   field references
+--echo #
+
+CREATE TABLE t1 (
+  a int,
+  b int,
+  UNIQUE (a), KEY (b)
+);
+INSERT INTO t1 VALUES (1,1), (2,1);
+
+CREATE TABLE st1 like t1;
+INSERT INTO st1 VALUES (1,1), (2,1);
+
+CREATE TABLE st2 like t1;
+INSERT INTO st2 VALUES (1,1), (2,1);
+
+# should have "impossible where"
+EXPLAIN
+SELECT MAX(b), (SELECT COUNT(*) FROM st1,st2 WHERE st2.b <= t1.b)
+FROM t1 
+WHERE a = 230;
+
+# should not crash
+SELECT MAX(b), (SELECT COUNT(*) FROM st1,st2 WHERE st2.b <= t1.b)
+FROM t1 
+WHERE a = 230;
+
+DROP TABLE t1, st1, st2;
+
 --echo End of 5.0 tests.
 
 #

sql/sql_select.cc

@@ -3299,6 +3299,28 @@ add_key_equal_fields(KEY_FIELD **key_fields, uint and_level,
   }
 }
 
+
+/**
+  Check if an expression is a non-outer field.
+
+  Checks if an expression is a field and belongs to the current select.
+
+  @param   field  Item expression to check
+
+  @return boolean
+     @retval TRUE   the expression is a local field
+     @retval FALSE  it's something else
+*/
+
+inline static bool
+is_local_field (Item *field)
+{
+  field= field->real_item();
+  return field->type() == Item::FIELD_ITEM && 
+    !((Item_field *)field)->depended_from;
+}
+
+
 static void
 add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
                COND *cond, table_map usable_tables,
@@ -3374,13 +3396,12 @@ add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
   {
     Item **values;
     // BETWEEN, IN, NE
-    if (cond_func->key_item()->real_item()->type() == Item::FIELD_ITEM &&
+    if (is_local_field (cond_func->key_item()) &&
 	!(cond_func->used_tables() & OUTER_REF_TABLE_BIT))
     {
       values= cond_func->arguments()+1;
       if (cond_func->functype() == Item_func::NE_FUNC &&
-        cond_func->arguments()[1]->real_item()->type() == Item::FIELD_ITEM &&
+        is_local_field (cond_func->arguments()[1]))
-	     !(cond_func->arguments()[0]->used_tables() & OUTER_REF_TABLE_BIT))
         values--;
       DBUG_ASSERT(cond_func->functype() != Item_func::IN_FUNC ||
                   cond_func->argument_count() != 2);
@@ -3396,9 +3417,7 @@ add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
       for (uint i= 1 ; i < cond_func->argument_count() ; i++)
       {
         Item_field *field_item;
-        if (cond_func->arguments()[i]->real_item()->type() == Item::FIELD_ITEM
+        if (is_local_field (cond_func->arguments()[i]))
-            &&
-            !(cond_func->arguments()[i]->used_tables() & OUTER_REF_TABLE_BIT))
         {
           field_item= (Item_field *) (cond_func->arguments()[i]->real_item());
           add_key_equal_fields(key_fields, *and_level, cond_func,
@@ -3414,8 +3433,7 @@ add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
     bool equal_func=(cond_func->functype() == Item_func::EQ_FUNC ||
 		     cond_func->functype() == Item_func::EQUAL_FUNC);
 
-    if (cond_func->arguments()[0]->real_item()->type() == Item::FIELD_ITEM &&
+    if (is_local_field (cond_func->arguments()[0]))
-	!(cond_func->arguments()[0]->used_tables() & OUTER_REF_TABLE_BIT))
     {
       add_key_equal_fields(key_fields, *and_level, cond_func,
 	                (Item_field*) (cond_func->arguments()[0])->real_item(),
@@ -3423,9 +3441,8 @@ add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
                            cond_func->arguments()+1, 1, usable_tables,
                            sargables);
     }
-    if (cond_func->arguments()[1]->real_item()->type() == Item::FIELD_ITEM &&
+    if (is_local_field (cond_func->arguments()[1]) &&
-	cond_func->functype() != Item_func::LIKE_FUNC &&
+	cond_func->functype() != Item_func::LIKE_FUNC)
-	!(cond_func->arguments()[1]->used_tables() & OUTER_REF_TABLE_BIT))
     {
       add_key_equal_fields(key_fields, *and_level, cond_func, 
                        (Item_field*) (cond_func->arguments()[1])->real_item(),
@@ -3437,7 +3454,7 @@ add_key_fields(JOIN *join, KEY_FIELD **key_fields, uint *and_level,
   }
   case Item_func::OPTIMIZE_NULL:
     /* column_name IS [NOT] NULL */
-    if (cond_func->arguments()[0]->real_item()->type() == Item::FIELD_ITEM &&
+    if (is_local_field (cond_func->arguments()[0]) &&
 	!(cond_func->used_tables() & OUTER_REF_TABLE_BIT))
     {
       Item *tmp=new Item_null;