Bug #37348: Crash in or immediately after JOIN::make_sum_func_list

      
The optimizer pulls up aggregate functions which should be aggregated in
an outer select. At some point it may substitute such a function for a field
in the temporary table. The setup_copy_fields function doesn't take this
into account and may overrun the copy_field buffer.
      
Fixed by filtering out the fields referenced through the specialized
reference for aggregates (Item_aggregate_ref).
Added an assertion to make sure bugs that cause similar discrepancy 
don't go undetected.

mysql-test/r/func_group.result:
  Bug #37348: test case
mysql-test/t/func_group.test:
  Bug #37348: test case
sql/item.cc:
  Bug #37348: Added a way to distinguish Item_aggregate_ref from the other types of refs
sql/item.h:
  Bug #37348: Added a way to distinguish Item_aggregate_ref from the other types of refs
sql/sql_select.cc:
  Bug #37348: 
   - Don't consider copying field references
      seen through Item_aggregate_ref
   - check for discrepancies between the number of expected 
     fields that need copying and the actual fields copied.

mysql-test/r/func_group.result

@@ -1416,4 +1416,41 @@ SELECT AVG(a), CAST(AVG(a) AS DECIMAL) FROM t1;
 AVG(a)	CAST(AVG(a) AS DECIMAL)
 15	15
 DROP TABLE t1;
+CREATE TABLE derived1 (a bigint(21));
+INSERT INTO derived1 VALUES (2);
+CREATE TABLE D (
+pk int(11) NOT NULL AUTO_INCREMENT,
+int_nokey int(11) DEFAULT NULL,
+int_key int(11) DEFAULT NULL,
+filler blob,
+PRIMARY KEY (pk),
+KEY int_key (int_key)
+);
+INSERT INTO D VALUES 
+(39,40,4,repeat('  X', 42)),
+(43,56,4,repeat('  X', 42)),
+(47,12,4,repeat('  X', 42)),
+(71,28,4,repeat('  X', 42)),
+(76,54,4,repeat('  X', 42)),
+(83,45,4,repeat('  X', 42)),
+(105,53,12,NULL);
+SELECT 
+(SELECT COUNT( int_nokey ) 
+FROM derived1 AS X 
+WHERE 
+X.int_nokey < 61 
+GROUP BY pk 
+LIMIT 1) 
+FROM D AS X 
+WHERE X.int_key < 13  
+GROUP BY int_nokey LIMIT 1;
+(SELECT COUNT( int_nokey ) 
+FROM derived1 AS X 
+WHERE 
+X.int_nokey < 61 
+GROUP BY pk 
+LIMIT 1)
+1
+DROP TABLE derived1;
+DROP TABLE D;
 End of 5.0 tests

mysql-test/t/func_group.test

@@ -933,5 +933,45 @@ SELECT AVG(a), CAST(AVG(a) AS DECIMAL) FROM t1;
 
 DROP TABLE t1;
 
+#
+# Bug #37348: Crash in or immediately after JOIN::make_sum_func_list
+#
+
+CREATE TABLE derived1 (a bigint(21));
+INSERT INTO derived1 VALUES (2);
+
+
+CREATE TABLE D (
+  pk int(11) NOT NULL AUTO_INCREMENT,
+  int_nokey int(11) DEFAULT NULL,
+  int_key int(11) DEFAULT NULL,
+  filler blob,
+  PRIMARY KEY (pk),
+  KEY int_key (int_key)
+);
+
+INSERT INTO D VALUES 
+  (39,40,4,repeat('  X', 42)),
+  (43,56,4,repeat('  X', 42)),
+  (47,12,4,repeat('  X', 42)),
+  (71,28,4,repeat('  X', 42)),
+  (76,54,4,repeat('  X', 42)),
+  (83,45,4,repeat('  X', 42)),
+  (105,53,12,NULL);
+
+SELECT 
+  (SELECT COUNT( int_nokey ) 
+   FROM derived1 AS X 
+   WHERE 
+     X.int_nokey < 61 
+   GROUP BY pk 
+   LIMIT 1) 
+FROM D AS X 
+WHERE X.int_key < 13  
+GROUP BY int_nokey LIMIT 1;
+
+DROP TABLE derived1;
+DROP TABLE D;
+
 ###
 --echo End of 5.0 tests

sql/item.cc

@@ -1338,6 +1338,7 @@ class Item_aggregate_ref : public Item_ref
     else
       Item_ident::print(str, query_type);
   }
+  virtual Ref_Type ref_type() { return AGGREGATE_REF; }
 };
 
 

sql/item.h

@@ -2126,7 +2126,7 @@ class Item_ref :public Item_ident
 protected:
   void set_properties();
 public:
-  enum Ref_Type { REF, DIRECT_REF, VIEW_REF, OUTER_REF };
+  enum Ref_Type { REF, DIRECT_REF, VIEW_REF, OUTER_REF, AGGREGATE_REF };
   Field *result_field;			 /* Save result here */
   Item **ref;
   Item_ref(Name_resolution_context *context_arg,

sql/sql_select.cc

@@ -14804,6 +14804,7 @@ setup_copy_fields(THD *thd, TMP_TABLE_PARAM *param,
   Item *pos;
   List_iterator_fast<Item> li(all_fields);
   Copy_field *copy= NULL;
+  IF_DBUG(Copy_field *copy_start);
   res_selected_fields.empty();
   res_all_fields.empty();
   List_iterator_fast<Item> itr(res_all_fields);
@@ -14816,12 +14817,19 @@ setup_copy_fields(THD *thd, TMP_TABLE_PARAM *param,
     goto err2;
 
   param->copy_funcs.empty();
+  IF_DBUG(copy_start= copy);
   for (i= 0; (pos= li++); i++)
   {
     Field *field;
     uchar *tmp;
     Item *real_pos= pos->real_item();
-    if (real_pos->type() == Item::FIELD_ITEM)
+    /*
+      Aggregate functions can be substituted for fields (by e.g. temp tables).
+      We need to filter those substituted fields out.
+    */
+    if (real_pos->type() == Item::FIELD_ITEM &&
+        !(real_pos != pos &&
+          ((Item_ref *)pos)->ref_type() == Item_ref::AGGREGATE_REF))
     {
       Item_field *item;
       if (!(item= new Item_field(thd, ((Item_field*) real_pos))))
@@ -14868,6 +14876,7 @@ setup_copy_fields(THD *thd, TMP_TABLE_PARAM *param,
 	  goto err;
         if (copy)
         {
+          DBUG_ASSERT (param->field_count > (uint) (copy - copy_start));
           copy->set(tmp, item->result_field);
           item->result_field->move_field(copy->to_ptr,copy->to_null_ptr,1);
 #ifdef HAVE_purify