expression: fix BIT type columns are not padded with left zeros (#25575)

pingcap · Jun 21, 2021 · 6454885 · 6454885
1 parent 9f18723
commit 6454885
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Showing 3 changed files with 17 additions and 3 deletions.
diff --git a/executor/executor_test.go b/executor/executor_test.go
@@ -8655,3 +8655,15 @@ func (s *testStaleTxnSuite) TestInvalidReadTemporaryTable(c *C) {
 		tk.MustGetErrMsg(query.sql, "can not read temporary table when 'tidb_snapshot' is set")
 	}
 }
+
+func (s *testSuite) TestIssue25506(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists tbl_3, tbl_23")
+	tk.MustExec("create table tbl_3 (col_15 bit(20))")
+	tk.MustExec("insert into tbl_3 values (0xFFFF)")
+	tk.MustExec("insert into tbl_3 values (0xFF)")
+	tk.MustExec("create table tbl_23 (col_15 bit(15))")
+	tk.MustExec("insert into tbl_23 values (0xF)")
+	tk.MustQuery("(select col_15 from tbl_23) union all (select col_15 from tbl_3 for update)").Check(testkit.Rows("\x00\x00\x0F", "\x00\xFF\xFF", "\x00\x00\xFF"))
+}
diff --git a/expression/chunk_executor.go b/expression/chunk_executor.go
@@ -125,11 +125,12 @@ func evalOneVec(ctx sessionctx.Context, expr Expression, input *chunk.Chunk, out
 			i64s := result.Int64s()
 			buf := chunk.NewColumn(ft, input.NumRows())
 			buf.ReserveBytes(input.NumRows())
+			byteSize := (ft.Flen + 7) >> 3
 			for i := range i64s {
 				if result.IsNull(i) {
 					buf.AppendNull()
 				} else {
-					buf.AppendBytes(types.NewBinaryLiteralFromUint(uint64(i64s[i]), -1))
+					buf.AppendBytes(types.NewBinaryLiteralFromUint(uint64(i64s[i]), byteSize))
 				}
 			}
 			// TODO: recycle all old Columns returned here.
@@ -262,7 +263,8 @@ func executeToInt(ctx sessionctx.Context, expr Expression, fieldType *types.Fiel
 		return nil
 	}
 	if fieldType.Tp == mysql.TypeBit {
-		output.AppendBytes(colID, types.NewBinaryLiteralFromUint(uint64(res), -1))
+		byteSize := (fieldType.Flen + 7) >> 3
+		output.AppendBytes(colID, types.NewBinaryLiteralFromUint(uint64(res), byteSize))
 		return nil
 	}
 	if fieldType.Tp == mysql.TypeEnum {

diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -3861,7 +3861,7 @@ func (s *testIntegrationSuite) TestCompareBuiltin(c *C) {
 
 	result = tk.MustQuery("select coalesce(NULL, a), coalesce(NULL, b, a), coalesce(c, NULL, a, b), coalesce(d, NULL), coalesce(d, c), coalesce(NULL, NULL, e, 1), coalesce(f), coalesce(1, a, b, c, d, e, f) from t2")
 	// coalesce(col_bit) is not same with MySQL, because it's a bug of MySQL(https://bugs.mysql.com/bug.php?id=103289&thanks=4)
-	result.Check(testkit.Rows(fmt.Sprintf("1 1.1 2017-08-01 12:01:01 12:01:01 %s 12:01:01 abcdef \x15 1", time.Now().In(tk.Se.GetSessionVars().Location()).Format("2006-01-02"))))
+	result.Check(testkit.Rows(fmt.Sprintf("1 1.1 2017-08-01 12:01:01 12:01:01 %s 12:01:01 abcdef \x00\x15 1", time.Now().In(tk.Se.GetSessionVars().Location()).Format("2006-01-02"))))
 
 	// nullif
 	result = tk.MustQuery(`SELECT NULLIF(NULL, 1), NULLIF(1, NULL), NULLIF(1, 1), NULLIF(NULL, NULL);`)