vtgateconn correctly receieves errors when they're sent in the RPC response for Execute*, tests pass

go/vt/vtgate/gorpcvtgateconn/conn.go

@@ -17,6 +17,7 @@ import (
 	"github.com/youtube/vitess/go/vt/rpc"
 	tproto "github.com/youtube/vitess/go/vt/tabletserver/proto"
 	"github.com/youtube/vitess/go/vt/topo"
+	"github.com/youtube/vitess/go/vt/vterrors"
 	"github.com/youtube/vitess/go/vt/vtgate/proto"
 	"github.com/youtube/vitess/go/vt/vtgate/vtgateconn"
 	"golang.org/x/net/context"
@@ -61,6 +62,9 @@ func (conn *vtgateConn) Execute(ctx context.Context, query string, bindVars map[
 	if result.Error != "" {
 		return nil, result.Session, errors.New(result.Error)
 	}
+	if err := vterrors.FromRPCError(result.Err); err != nil {
+		return nil, result.Session, err
+	}
 	return result.Result, result.Session, nil
 }
 
@@ -85,6 +89,9 @@ func (conn *vtgateConn) ExecuteShard(ctx context.Context, query string, keyspace
 	if result.Error != "" {
 		return nil, result.Session, errors.New(result.Error)
 	}
+	if err := vterrors.FromRPCError(result.Err); err != nil {
+		return nil, result.Session, err
+	}
 	return result.Result, result.Session, nil
 }
 
@@ -109,6 +116,9 @@ func (conn *vtgateConn) ExecuteKeyspaceIds(ctx context.Context, query string, ke
 	if result.Error != "" {
 		return nil, result.Session, errors.New(result.Error)
 	}
+	if err := vterrors.FromRPCError(result.Err); err != nil {
+		return nil, result.Session, err
+	}
 	return result.Result, result.Session, nil
 }
 
@@ -133,6 +143,9 @@ func (conn *vtgateConn) ExecuteKeyRanges(ctx context.Context, query string, keys
 	if result.Error != "" {
 		return nil, result.Session, errors.New(result.Error)
 	}
+	if err := vterrors.FromRPCError(result.Err); err != nil {
+		return nil, result.Session, err
+	}
 	return result.Result, result.Session, nil
 }
 
@@ -158,6 +171,9 @@ func (conn *vtgateConn) ExecuteEntityIds(ctx context.Context, query string, keys
 	if result.Error != "" {
 		return nil, result.Session, errors.New(result.Error)
 	}
+	if err := vterrors.FromRPCError(result.Err); err != nil {
+		return nil, result.Session, err
+	}
 	return result.Result, result.Session, nil
 }
 

go/vt/vtgate/proto/query_result_bson.go

@@ -33,6 +33,12 @@ func (queryResult *QueryResult) MarshalBson(buf *bytes2.ChunkedWriter, key strin
 		(*queryResult.Session).MarshalBson(buf, "Session")
 	}
 	bson.EncodeString(buf, "Error", queryResult.Error)
+	// *mproto.RPCError
+	if queryResult.Err == nil {
+		bson.EncodePrefix(buf, bson.Null, "Err")
+	} else {
+		(*queryResult.Err).MarshalBson(buf, "Err")
+	}
 
 	lenWriter.Close()
 }
@@ -65,6 +71,12 @@ func (queryResult *QueryResult) UnmarshalBson(buf *bytes.Buffer, kind byte) {
 			}
 		case "Error":
 			queryResult.Error = bson.DecodeString(buf, kind)
+		case "Err":
+			// *mproto.RPCError
+			if kind != bson.Null {
+				queryResult.Err = new(mproto.RPCError)
+				(*queryResult.Err).UnmarshalBson(buf, kind)
+			}
 		default:
 			bson.Skip(buf, kind)
 		}