expression: Fix wrong way to check for overflow (#27122)

pingcap · Aug 20, 2021 · 949dafb · 949dafb
1 parent 086a63f
commit 949dafb
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Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/expression/builtin_arithmetic_vec.go b/expression/builtin_arithmetic_vec.go
@@ -921,7 +921,7 @@ func (b *builtinArithmeticPlusIntSig) plusUS(result *chunk.Column, lhi64s, rhi64
 			}
 			return types.ErrOverflow.GenWithStackByArgs("BIGINT UNSIGNED", fmt.Sprintf("(%s + %s)", b.args[0].String(), b.args[1].String()))
 		}
-		if rh > 0 && uint64(lh) > math.MaxUint64-uint64(lh) {
+		if rh > 0 && uint64(lh) > math.MaxUint64-uint64(rh) {
 			if result.IsNull(i) {
 				continue
 			}

diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -10260,3 +10260,9 @@ func (s *testIntegrationSuite) TestIssue27236(c *C) {
 	row = tk.MustQuery(`select extract(hour_second from c1) from t order by c1;`)
 	row.Check(testkit.Rows("-8385959", "7005959"))
 }
+
+func (s *testIntegrationSuite) TestIssue26977(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	result := tk.MustQuery("select a + 1 as f from (select cast(0xfffffffffffffff0 as unsigned) as a union select cast(1 as unsigned)) t having f != 2;")
+	result.Check(testkit.Rows("18446744073709551601"))
+}