NATURAL LEFT JOIN with a NOT predicate results in a server panic

[mrigger]

Consider the following statements:

CREATE TABLE t0(c0 INT);
CREATE TABLE t1(c0 INT);
SELECT * FROM t1 NATURAL LEFT JOIN t0 WHERE NOT t1.c0;

Unexpectedly, the SELECT results in a loss of connection:

mysql> CREATE TABLE t0(c0 INT);
Query OK, 0 rows affected (0.00 sec)

mysql> CREATE TABLE t1(c0 INT);
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT * FROM  t1 NATURAL LEFT JOIN t0 WHERE NOT t1.c0;
ERROR 2013 (HY000): Lost connection to MySQL server during query

The server logs the following:

[2020/04/15 12:09:14.241 +02:00] [ERROR] [conn.go:662] ["connection running loop panic"] [conn=1] [lastSQL="SELECT * FROM  t1 NATURAL LEFT JOIN t0 WHERE NOT t1.c0"] [err="ctx should not be nil"] [stack="goroutine 356 [running]:\ngithub.com/pingcap/tidb/server.(*clientConn).Run.func1(0x2d69d40, 0xc021d26930, 0xc001142340)\n\t/tidb/server/conn.go:660 +0xee\npanic(0x2634780, 0x2cfa0e0)\n\t/usr/lib/go-1.13/src/runtime/panic.go:679 +0x1b2\ngithub.com/pingcap/tidb/expression.newBaseBuiltinFuncWithTp(0x0, 0x0, 0xc0010c38e0, 0x1, 0x1, 0x0, 0xc000b7fe17, 0x1, 0x1, 0x0, ...)\n\t/tidb/expression/builtin.go:116 +0xc8d\ngithub.com/pingcap/tidb/expression.(*isTrueOrFalseFunctionClass).getFunction(0xc000b7ff88, 0x0, 0x0, 0xc0010c38e0, 0x1, 0x1, 0x2854860, 0x1, 0xc001034d10, 0xc000b800d0)\n\t/tidb/expression/builtin_op.go:421 +0x15b\ngithub.com/pingcap/tidb/expression.wrapWithIsTrue(0x0, 0x0, 0x1, 0x2dd2020, 0xc00103e780, 0x1, 0x7f25f01aac78, 0x8, 0xf08826, 0xc0010c37f0)\n\t/tidb/expression/expression.go:1125 +0x187\ngithub.com/pingcap/tidb/expression.pushNotAcrossExpr(0x0, 0x0, 0x2dd23e0, 0xc000a6e050, 0x0, 0x8, 0x1, 0x203000)\n\t/tidb/expression/util.go:398 +0x941\ngithub.com/pingcap/tidb/expression.PushDownNot(...)\n\t/tidb/expression/util.go:444\ngithub.com/pingcap/tidb/planner/core.isNullRejected(0x2da3400, 0xc000556d00, 0xc01ed33230, 0x2dd23e0, 0xc000a6e050, 0x203007)\n\t/tidb/planner/core/rule_predicate_push_down.go:336 +0x4c\ngithub.com/pingcap/tidb/planner/core.simplifyOuterJoin(0xc000537b00, 0xc0010c38b0, 0x1, 0x1)\n\t/tidb/planner/core/rule_predicate_push_down.go:319 +0x154\ngithub.com/pingcap/tidb/planner/core.(*LogicalJoin).PredicatePushDown(0xc000537b00, 0xc0010c38b0, 0x1, 0x1, 0x435b0c0, 0x0, 0x0, 0x0, 0x1)\n\t/tidb/planner/core/rule_predicate_push_down.go:114 +0x6a\ngithub.com/pingcap/tidb/planner/core.(*LogicalSelection).PredicatePushDown(0xc02209d290, 0x435b0c0, 0x0, 0x0, 0xf4300c, 0x0, 0x28e60e0, 0xc00103e701, 0x435b0c0)\n\t/tidb/planner/core/rule_predicate_push_down.go:77 +0x166\ngithub.com/pingcap/tidb/planner/core.(*baseLogicalPlan).PredicatePushDown(0xc001034c80, 0x435b0c0, 0x0, 0x0, 0xc0010c37f0, 0x1, 0x1, 0x1, 0x2da2300)\n\t/tidb/planner/core/rule_predicate_push_down.go:56 +0xa6\ngithub.com/pingcap/tidb/planner/core.(*LogicalProjection).PredicatePushDown(0xc001034c60, 0x0, 0x0, 0x0, 0x435c5a0, 0xc01ed33500, 0xc00126d470, 0x27b5040, 0xc00126d470)\n\t/tidb/planner/core/rule_predicate_push_down.go:371 +0x278\ngithub.com/pingcap/tidb/planner/core.(*ppdSolver).optimize(0x435ab60, 0x2d69d40, 0xc021d26930, 0x2da2200, 0xc001034c60, 0x2da2200, 0xc001034c60, 0x0, 0x0)\n\t/tidb/planner/core/rule_predicate_push_down.go:29 +0x42\ngithub.com/pingcap/tidb/planner/core.logicalOptimize(0x2d69d40, 0xc021d26930, 0x21a2, 0x2da2200, 0xc001034c60, 0xf069aa, 0x28adac0, 0x2984de0, 0x2d25001)\n\t/tidb/planner/core/optimizer.go:155 +0x116\ngithub.com/pingcap/tidb/planner/core.DoOptimize(0x2d69d40, 0xc021d26930, 0x2da3400, 0xc000556d00, 0x21a2, 0x2da2200, 0xc001034c60, 0x0, 0x0, 0x0, ...)\n\t/tidb/planner/core/optimizer.go:124 +0x60\ngithub.com/pingcap/tidb/planner.optimize(0x2d69d40, 0xc021d26930, 0x2da3400, 0xc000556d00, 0x2d6b8c0, 0xc00056c9c0, 0x2d98740, 0xc01ed32900, 0x0, 0x0, ...)\n\t/tidb/planner/optimize.go:189 +0x5a9\ngithub.com/pingcap/tidb/planner.Optimize(0x2d69d40, 0xc021d26930, 0x2da3400, 0xc000556d00, 0x2d6b8c0, 0xc00056c9c0, 0x2d98740, 0xc01ed32900, 0x0, 0x0, ...)\n\t/tidb/planner/optimize.go:63 +0x28f\ngithub.com/pingcap/tidb/executor.(*Compiler).Compile(0xc000b80f30, 0x2d69d40, 0xc021d26930, 0x2d71100, 0xc00056c9c0, 0x0, 0x0, 0x0)\n\t/tidb/executor/compiler.go:61 +0x253\ngithub.com/pingcap/tidb/session.(*session).ExecuteStmt(0xc000556d00, 0x2d69d40, 0xc021d26930, 0x2d71100, 0xc00056c9c0, 0x0, 0x0, 0x0, 0x0)\n\t/tidb/ses"]

I found this based on the latest master commit (8f000fc):

+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                                                          |
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v4.0.0-beta.2-254-g8f000fc35
Git Commit Hash: 8f000fc353f858de3148a7857b398380118088c3
Git Branch: master
UTC Build Time: 2020-04-15 10:08:36
GoVersion: go1.13.4
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

The 4.0 RC seems not be affected by this.

[XuHuaiyu]

fixed in #16430