Backport of bug #55564 to 5.0-security

mysql-test/r/user_var.result

@@ -378,4 +378,21 @@ FROM t1,t2 WHERE t1.f1 = t2.f1 ORDER BY t2.f1;
 MIN(t2.f1)	@bar:= (SELECT MIN(t3.f2) FROM t3 WHERE t3.f2 > foo)
 10	NULL
 DROP TABLE t1, t2, t3;
+CREATE TABLE t1(a INT);
+INSERT INTO t1 VALUES (0),(0);
+# BUG#55615 : should not crash
+SELECT (@a:=((SELECT @a:=1 FROM t1 LIMIT 1))) AND COUNT(1) FROM t1 GROUP BY @a;
+(@a:=((SELECT @a:=1 FROM t1 LIMIT 1))) AND COUNT(1)
+1
+1
+# BUG#55564 : should not crash
+SELECT IF(
+@v:=LEAST((SELECT 1 FROM t1 t2 LEFT JOIN t1 ON (@v) GROUP BY t1.a), a),
+count(*), 1) 
+FROM t1 GROUP BY a LIMIT 1;
+IF(
+@v:=LEAST((SELECT 1 FROM t1 t2 LEFT JOIN t1 ON (@v) GROUP BY t1.a), a),
+count(*), 1)
+1
+DROP TABLE t1;
 End of 5.0 tests

mysql-test/t/user_var.test

@@ -268,4 +268,24 @@ FROM t1,t2 WHERE t1.f1 = t2.f1 ORDER BY t2.f1;
 
 DROP TABLE t1, t2, t3;
 
+
+#
+# Bug #55615: debug assertion after using variable in assignment and
+# referred to
+# Bug #55564: crash with user variables, assignments, joins...
+#
+
+CREATE TABLE t1(a INT);
+INSERT INTO t1 VALUES (0),(0);
+--echo # BUG#55615 : should not crash
+SELECT (@a:=((SELECT @a:=1 FROM t1 LIMIT 1))) AND COUNT(1) FROM t1 GROUP BY @a;
+--echo # BUG#55564 : should not crash
+SELECT IF(
+  @v:=LEAST((SELECT 1 FROM t1 t2 LEFT JOIN t1 ON (@v) GROUP BY t1.a), a),
+  count(*), 1) 
+FROM t1 GROUP BY a LIMIT 1;
+
+DROP TABLE t1;
+
+
 --echo End of 5.0 tests

sql/item_func.cc

@@ -4303,6 +4303,14 @@ longlong Item_func_set_user_var::val_int_result()
   return entry->val_int(&null_value);
 }
 
+bool Item_func_set_user_var::val_bool_result()
+{
+  DBUG_ASSERT(fixed == 1);
+  check(TRUE);
+  update();					// Store expression
+  return entry->val_int(&null_value) != 0;
+}
+
 String *Item_func_set_user_var::str_result(String *str)
 {
   DBUG_ASSERT(fixed == 1);

sql/item_func.h

@@ -1300,6 +1300,7 @@ class Item_func_set_user_var :public Item_func
   my_decimal *val_decimal(my_decimal *);
   double val_result();
   longlong val_int_result();
+  bool val_bool_result();
   String *str_result(String *str);
   my_decimal *val_decimal_result(my_decimal *);
   bool is_null_result();