feat: implement copilot mode

vendor/google.golang.org/protobuf/encoding/prototext/encode.go

@@ -101,13 +101,19 @@ func (o MarshalOptions) Format(m proto.Message) string {
 // MarshalOptions object. Do not depend on the output being stable. It may
 // change over time across different versions of the program.
 func (o MarshalOptions) Marshal(m proto.Message) ([]byte, error) {
-	return o.marshal(m)
+	return o.marshal(nil, m)
+}
+
+// MarshalAppend appends the textproto format encoding of m to b,
+// returning the result.
+func (o MarshalOptions) MarshalAppend(b []byte, m proto.Message) ([]byte, error) {
+	return o.marshal(b, m)
 }
 
 // marshal is a centralized function that all marshal operations go through.
 // For profiling purposes, avoid changing the name of this function or
 // introducing other code paths for marshal that do not go through this.
-func (o MarshalOptions) marshal(m proto.Message) ([]byte, error) {
+func (o MarshalOptions) marshal(b []byte, m proto.Message) ([]byte, error) {
 	var delims = [2]byte{'{', '}'}
 
 	if o.Multiline && o.Indent == "" {
@@ -117,7 +123,7 @@ func (o MarshalOptions) marshal(m proto.Message) ([]byte, error) {
 		o.Resolver = protoregistry.GlobalTypes
 	}
 
-	internalEnc, err := text.NewEncoder(o.Indent, delims, o.EmitASCII)
+	internalEnc, err := text.NewEncoder(b, o.Indent, delims, o.EmitASCII)
 	if err != nil {
 		return nil, err
 	}
@@ -125,7 +131,7 @@ func (o MarshalOptions) marshal(m proto.Message) ([]byte, error) {
 	// Treat nil message interface as an empty message,
 	// in which case there is nothing to output.
 	if m == nil {
-		return []byte{}, nil
+		return b, nil
 	}
 
 	enc := encoder{internalEnc, o}

vendor/google.golang.org/protobuf/encoding/protowire/wire.go

@@ -3,7 +3,7 @@
 // license that can be found in the LICENSE file.
 
 // Package protowire parses and formats the raw wire encoding.
-// See https://developers.google.com/protocol-buffers/docs/encoding.
+// See https://protobuf.dev/programming-guides/encoding.
 //
 // For marshaling and unmarshaling entire protobuf messages,
 // use the "google.golang.org/protobuf/proto" package instead.
@@ -29,12 +29,8 @@ const (
 )
 
 // IsValid reports whether the field number is semantically valid.
-//
-// Note that while numbers within the reserved range are semantically invalid,
-// they are syntactically valid in the wire format.
-// Implementations may treat records with reserved field numbers as unknown.
 func (n Number) IsValid() bool {
-	return MinValidNumber <= n && n < FirstReservedNumber || LastReservedNumber < n && n <= MaxValidNumber
+	return MinValidNumber <= n && n <= MaxValidNumber
 }
 
 // Type represents the wire type.