ddl: tidb panic while query hash partition table with is null condition

planner/core/integration_test.go

@@ -3473,6 +3473,20 @@ func (s *testIntegrationSuite) TestIssue23736(c *C) {
 	c.Assert(tk.MustUseIndex("select /*+ stream_agg() */ count(1) from t0 where c > 10 and b < 2", "c"), IsFalse)
 }
 
+// https://github.com/pingcap/tidb/issues/23802
+func (s *testIntegrationSuite) TestPanicWhileQueryTableWithIsNull(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+
+	tk.MustExec("drop table if exists NT_HP27193")
+	tk.MustExec("CREATE TABLE `NT_HP27193` (  `COL1` int(20) DEFAULT NULL,  `COL2` varchar(20) DEFAULT NULL,  `COL4` datetime DEFAULT NULL,  `COL3` bigint(20) DEFAULT NULL,  `COL5` float DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin PARTITION BY HASH ( `COL1`%`COL3` ) PARTITIONS 10;")
+	_, err := tk.Exec("select col1 from NT_HP27193 where col1 is null;")
+	c.Assert(err, IsNil)
+	tk.MustExec("INSERT INTO NT_HP27193 (COL2, COL4, COL3, COL5) VALUES ('m',  '2020-05-04 13:15:27', 8,  2602)")
+	_, err = tk.Exec("select col1 from NT_HP27193 where col1 is null;")
+	c.Assert(err, IsNil)
+}
+
 func (s *testIntegrationSuite) TestIssue23846(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	tk.MustExec("use test")

planner/core/rule_partition_processor.go

@@ -128,11 +128,11 @@ func (s *partitionProcessor) findUsedPartitions(ctx sessionctx.Context, tbl tabl
 		partIdx[i].Index = i
 		colLen = append(colLen, types.UnspecifiedLength)
 	}
-	datchedResult, err := ranger.DetachCondAndBuildRangeForPartition(ctx, conds, partIdx, colLen)
+	detachedResult, err := ranger.DetachCondAndBuildRangeForPartition(ctx, conds, partIdx, colLen)
 	if err != nil {
 		return nil, nil, err
 	}
-	ranges := datchedResult.Ranges
+	ranges := detachedResult.Ranges
 	used := make([]int, 0, len(ranges))
 	for _, r := range ranges {
 		if r.IsPointNullable(ctx.GetSessionVars().StmtCtx) {
@@ -142,7 +142,10 @@ func (s *partitionProcessor) findUsedPartitions(ctx sessionctx.Context, tbl tabl
 					break
 				}
 			}
-			pos, isNull, err := pe.EvalInt(ctx, chunk.MutRowFromDatums(r.HighVal).ToRow())
+			highLowVals := make([]types.Datum, 0, len(r.HighVal)+len(r.LowVal))
+			highLowVals = append(highLowVals, r.HighVal...)
+			highLowVals = append(highLowVals, r.LowVal...)
+			pos, isNull, err := pe.EvalInt(ctx, chunk.MutRowFromDatums(highLowVals).ToRow())
 			if err != nil {
 				return nil, nil, err
 			}
@@ -170,7 +173,7 @@ func (s *partitionProcessor) findUsedPartitions(ctx sessionctx.Context, tbl tabl
 			ret = append(ret, used[i])
 		}
 	}
-	return ret, datchedResult.RemainedConds, nil
+	return ret, detachedResult.RemainedConds, nil
 }
 
 func (s *partitionProcessor) convertToIntSlice(or partitionRangeOR, pi *model.PartitionInfo, partitionNames []model.CIStr) []int {