merge

mysql-test/r/select.result

@@ -4427,6 +4427,20 @@ ROW(a,a) <=> ROW((SELECT 1 FROM t1 WHERE 1=2),(SELECT 1 FROM t1))
 INTO @var0;
 ERROR 21000: Subquery returns more than 1 row
 DROP TABLE t1;
+#
+# Bug #48458: simple query tries to allocate enormous amount of
+#   memory
+#
+CREATE TABLE t1(a INT NOT NULL, b YEAR);
+INSERT INTO t1 VALUES ();
+Warnings:
+Warning	1364	Field 'a' doesn't have a default value
+CREATE TABLE t2(c INT);
+# Should not err out because of out-of-memory
+SELECT 1 FROM t2 JOIN t1 ON 1=1
+WHERE a != '1' AND NOT a >= b OR NOT ROW(b,a )<> ROW(a,a);
+1
+DROP TABLE t1,t2;
 End of 5.0 tests
 create table t1(a INT, KEY (a));
 INSERT INTO t1 VALUES (1),(2),(3),(4),(5);

mysql-test/t/select.test

@@ -3772,6 +3772,19 @@ INTO @var0;
 
 DROP TABLE t1;
  
+--echo #
+--echo # Bug #48458: simple query tries to allocate enormous amount of
+--echo #   memory
+--echo #
+
+CREATE TABLE t1(a INT NOT NULL, b YEAR);
+INSERT INTO t1 VALUES ();
+CREATE TABLE t2(c INT);
+--echo # Should not err out because of out-of-memory
+SELECT 1 FROM t2 JOIN t1 ON 1=1
+  WHERE a != '1' AND NOT a >= b OR NOT ROW(b,a )<> ROW(a,a);
+DROP TABLE t1,t2;
+
 
 --echo End of 5.0 tests
 

sql/sql_select.cc

@@ -7834,12 +7834,12 @@ static COND *build_equal_items_for_cond(THD *thd, COND *cond,
         {
           item_equal->fix_length_and_dec();
           item_equal->update_used_tables();
+          set_if_bigger(thd->lex->current_select->max_equal_elems,
+                        item_equal->members());  
+          return item_equal;
 	}
-        else
-          item_equal= (Item_equal *) eq_list.pop();
-        set_if_bigger(thd->lex->current_select->max_equal_elems,
-                      item_equal->members());  
-        return item_equal;
+
+        return eq_list.pop();
       }
       else
       {