handle the case the type is set for SEND_LONG_DATA param

Signed-off-by: Yang Keao <yangkeao@chunibyo.icu>

pkg/server/conn_stmt_params.go

@@ -40,7 +40,30 @@ func parseBinaryParams(params []param.BinaryParam, boundParams [][]byte, nullBit
 		if boundParams[i] != nil {
 			params[i] = param.BinaryParam{
 				Tp:  mysql.TypeBlob,
-				Val: enc.DecodeInput(boundParams[i]),
+				Val: boundParams[i],
+			}
+
+			if (i<<1)+1 < len(paramTypes) {
+				// Set the type and unsigned flag for the parameter. It's still not clear whether every clients
+				// will pass the `paramTypes` of the param which has already been sent through `SEND_LONG_DATA`.
+				// Therefore, only set the type when it's given.
+				//
+				// Only `BLOB` or `STRING` type will be sent through `SEND_LONG_DATA`, because others are usually
+				// small.
+				tp := paramTypes[i<<1]
+				isUnsigned := (paramTypes[(i<<1)+1] & 0x80) > 0
+
+				switch tp {
+				case mysql.TypeVarchar, mysql.TypeVarString, mysql.TypeString, mysql.TypeBit:
+					params[i].Tp = tp
+					params[i].IsUnsigned = isUnsigned
+					params[i].Val = enc.DecodeInput(boundParams[i])
+				case mysql.TypeBlob, mysql.TypeTinyBlob, mysql.TypeMediumBlob, mysql.TypeLongBlob:
+					// TODO: check whether it needs to decode the data.
+					params[i].Tp = tp
+					params[i].IsUnsigned = isUnsigned
+					params[i].Val = boundParams[i]
+				}
 			}
 			continue
 		}

pkg/server/internal/testserverclient/server_client.go

@@ -2727,4 +2727,31 @@ func (cli *TestServerClient) RunTestConnectionCount(t *testing.T) {
 	})
 }
 
+func (cli *TestServerClient) RunTestTypeOfSendLongData(t *testing.T) {
+	cli.RunTests(t, func(config *mysql.Config) {
+		config.MaxAllowedPacket = 1024
+	}, func(dbt *testkit.DBTestKit) {
+		ctx := context.Background()
+
+		conn, err := dbt.GetDB().Conn(ctx)
+		require.NoError(t, err)
+		_, err = conn.ExecContext(ctx, "CREATE TABLE t (j JSON);")
+		require.NoError(t, err)
+
+		str := `"` + strings.Repeat("a", 1024) + `"`
+		stmt, err := conn.PrepareContext(ctx, "INSERT INTO t VALUES (cast(? as JSON));")
+		require.NoError(t, err)
+		_, err = stmt.ExecContext(ctx, str)
+		require.NoError(t, err)
+		result, err := conn.QueryContext(ctx, "SELECT j FROM t;")
+		require.NoError(t, err)
+
+		for result.Next() {
+			var j string
+			require.NoError(t, result.Scan(&j))
+			require.Equal(t, str, j)
+		}
+	})
+}
+
 //revive:enable:exported

pkg/server/tests/commontest/BUILD.bazel

@@ -8,7 +8,7 @@ go_test(
         "tidb_test.go",
     ],
     flaky = True,
-    shard_count = 49,
+    shard_count = 50,
     deps = [
         "//pkg/config",
         "//pkg/ddl/util",

pkg/server/tests/commontest/tidb_test.go

@@ -3082,3 +3082,8 @@ func TestConnectionCount(t *testing.T) {
 	ts := servertestkit.CreateTidbTestSuite(t)
 	ts.RunTestConnectionCount(t)
 }
+
+func TestTypeOfSendLongData(t *testing.T) {
+	ts := servertestkit.CreateTidbTestSuite(t)
+	ts.RunTestTypeOfSendLongData(t)
+}