table: set the collation correctly in CastValue

executor/write_test.go

@@ -1096,6 +1096,20 @@ func TestReplace(t *testing.T) {
 	tk.MustExec("drop table t1, t2")
 }
 
+func TestReplaceWithCICollation(t *testing.T) {
+	collate.SetNewCollationEnabledForTest(true)
+	defer collate.SetNewCollationEnabledForTest(false)
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+
+	tk.MustExec("create table t (a varchar(20) charset utf8mb4 collate utf8mb4_general_ci primary key);")
+	tk.MustExec("replace into t(a) values (_binary'A '),(_binary'A');")
+	tk.MustQuery("select a from t use index(primary);").Check(testkit.Rows("A"))
+	tk.MustQuery("select a from t ignore index(primary);").Check(testkit.Rows("A"))
+}
+
 func TestGeneratedColumnForInsert(t *testing.T) {
 	store, clean := testkit.CreateMockStore(t)
 	defer clean()

table/column.go

@@ -363,18 +363,18 @@ func validateStringDatum(ctx sessionctx.Context, origin, casted *types.Datum, co
 		src := casted.GetBytes()
 		encBytes, err := enc.Transform(nil, src, charset.OpDecode)
 		if err != nil {
-			casted.SetBytesAsString(encBytes, charset.CollationUTF8MB4, 0)
+			casted.SetBytesAsString(encBytes, col.Collate, 0)
 			nSrc := charset.CountValidBytesDecode(enc, src)
 			return handleWrongCharsetValue(ctx, col, src, nSrc)
 		}
-		casted.SetBytesAsString(encBytes, charset.CollationUTF8MB4, 0)
+		casted.SetBytesAsString(encBytes, col.Collate, 0)
 		return nil
 	}
 	// Check if the string is valid in the given column charset.
 	str := casted.GetBytes()
 	if !charset.IsValid(enc, str) {
 		replace, _ := enc.Transform(nil, str, charset.OpReplace)
-		casted.SetBytesAsString(replace, charset.CollationUTF8MB4, 0)
+		casted.SetBytesAsString(replace, col.Collate, 0)
 		nSrc := charset.CountValidBytes(enc, str)
 		return handleWrongCharsetValue(ctx, col, str, nSrc)
 	}