Bug #41156: List of derived tables acts like a chain of

            mutually-nested subqueries

Queries of the form

  SELECT * FROM (SELECT 1) AS t1,
                (SELECT 2) AS t2,...
                (SELECT 32) AS t32

caused the "Too high level of nesting for select" error
as if the query has a form

  SELECT * FROM (SELECT 1 FROM (SELECT 2 FROM (SELECT 3 FROM...


The table_factor parser rule has been modified to adjust
the LEX::nest_level variable value after every derived table.

mysql-test/r/derived.result

@@ -383,3 +383,21 @@ select t2.* from (select * from t1) as A inner join t2 on A.ID = t2.FID;
 ID	DATA	FID
 drop table t1, t2;
 drop user mysqltest_1;
+# End of 4.1 tests
+SELECT 0 FROM
+(SELECT 0) t01, (SELECT 0) t02, (SELECT 0) t03, (SELECT 0) t04, (SELECT 0) t05,
+(SELECT 0) t06, (SELECT 0) t07, (SELECT 0) t08, (SELECT 0) t09, (SELECT 0) t10,
+(SELECT 0) t11, (SELECT 0) t12, (SELECT 0) t13, (SELECT 0) t14, (SELECT 0) t15,
+(SELECT 0) t16, (SELECT 0) t17, (SELECT 0) t18, (SELECT 0) t19, (SELECT 0) t20,
+(SELECT 0) t21, (SELECT 0) t22, (SELECT 0) t23, (SELECT 0) t24, (SELECT 0) t25,
+(SELECT 0) t26, (SELECT 0) t27, (SELECT 0) t28, (SELECT 0) t29, (SELECT 0) t30,
+(SELECT 0) t31, (SELECT 0) t32, (SELECT 0) t33, (SELECT 0) t34, (SELECT 0) t35,
+(SELECT 0) t36, (SELECT 0) t37, (SELECT 0) t38, (SELECT 0) t39, (SELECT 0) t40,
+(SELECT 0) t41, (SELECT 0) t42, (SELECT 0) t43, (SELECT 0) t44, (SELECT 0) t45,
+(SELECT 0) t46, (SELECT 0) t47, (SELECT 0) t48, (SELECT 0) t49, (SELECT 0) t50,
+(SELECT 0) t51, (SELECT 0) t52, (SELECT 0) t53, (SELECT 0) t54, (SELECT 0) t55,
+(SELECT 0) t56, (SELECT 0) t57, (SELECT 0) t58, (SELECT 0) t59, (SELECT 0) t60,
+(SELECT 0) t61;
+0
+0
+# End of 5.0 tests

mysql-test/t/derived.test

@@ -279,4 +279,26 @@ disconnect con1;
 connection default;
 drop user mysqltest_1;
 
-# End of 4.1 tests
+--echo # End of 4.1 tests
+
+#
+# Bug #41156: List of derived tables acts like a chain of
+#             mutually-nested subqueries
+#
+
+SELECT 0 FROM
+(SELECT 0) t01, (SELECT 0) t02, (SELECT 0) t03, (SELECT 0) t04, (SELECT 0) t05,
+(SELECT 0) t06, (SELECT 0) t07, (SELECT 0) t08, (SELECT 0) t09, (SELECT 0) t10,
+(SELECT 0) t11, (SELECT 0) t12, (SELECT 0) t13, (SELECT 0) t14, (SELECT 0) t15,
+(SELECT 0) t16, (SELECT 0) t17, (SELECT 0) t18, (SELECT 0) t19, (SELECT 0) t20,
+(SELECT 0) t21, (SELECT 0) t22, (SELECT 0) t23, (SELECT 0) t24, (SELECT 0) t25,
+(SELECT 0) t26, (SELECT 0) t27, (SELECT 0) t28, (SELECT 0) t29, (SELECT 0) t30,
+(SELECT 0) t31, (SELECT 0) t32, (SELECT 0) t33, (SELECT 0) t34, (SELECT 0) t35,
+(SELECT 0) t36, (SELECT 0) t37, (SELECT 0) t38, (SELECT 0) t39, (SELECT 0) t40,
+(SELECT 0) t41, (SELECT 0) t42, (SELECT 0) t43, (SELECT 0) t44, (SELECT 0) t45,
+(SELECT 0) t46, (SELECT 0) t47, (SELECT 0) t48, (SELECT 0) t49, (SELECT 0) t50,
+(SELECT 0) t51, (SELECT 0) t52, (SELECT 0) t53, (SELECT 0) t54, (SELECT 0) t55,
+(SELECT 0) t56, (SELECT 0) t57, (SELECT 0) t58, (SELECT 0) t59, (SELECT 0) t60,
+(SELECT 0) t61; # 61 == MAX_TABLES
+
+--echo # End of 5.0 tests

sql/sql_yacc.yy

@@ -8493,6 +8493,7 @@ table_factor:
                 MYSQL_YYABORT;
               sel->add_joined_table($$);
               lex->pop_context();
+              lex->nest_level--;
             }
             else if ($4 || $6)
             {
@@ -8501,7 +8502,11 @@ table_factor:
               MYSQL_YYABORT;
             }
             else
+            {
+              /* nested join: FROM (t1 JOIN t2 ...),
+                 nest_level is the same as in the outer query */
               $$= $3;
+            }
           }
         ;