Ignore unknown tags in message set items (google#856)

formationgames · Jun 29, 2023 · 0eb3796 · 0eb3796
1 parent 2996e1d
commit 0eb3796
Show file tree

Hide file tree

Showing 3 changed files with 92 additions and 1 deletion.
diff --git a/protobuf/lib/src/protobuf/coded_buffer_reader.dart b/protobuf/lib/src/protobuf/coded_buffer_reader.dart
@@ -157,6 +157,34 @@ class CodedBufferReader {
     return _lastTag;
   }
 
+  bool skipField(int tag) {
+    final tagType = getTagWireType(tag);
+
+    if (isAtEnd() || tagType == WIRETYPE_END_GROUP) {
+      return false;
+    }
+
+    switch (getTagWireType(tag)) {
+      case WIRETYPE_VARINT:
+        readInt64();
+        return true;
+      case WIRETYPE_FIXED64:
+        readFixed64();
+        return true;
+      case WIRETYPE_LENGTH_DELIMITED:
+        readBytes();
+        return true;
+      case WIRETYPE_FIXED32:
+        readFixed32();
+        return true;
+      case WIRETYPE_START_GROUP:
+        readUnknownFieldSetGroup(getTagFieldNumber(tag));
+        return true;
+      default:
+        throw InvalidProtocolBufferException.invalidWireType();
+    }
+  }
+
   static int _decodeZigZag32(int value) {
     if ((value & 0x1) == 1) {
       return -(value >> 1) - 1;

diff --git a/protobuf/lib/src/protobuf/message_set.dart b/protobuf/lib/src/protobuf/message_set.dart
@@ -105,7 +105,10 @@ abstract class $_MessageSet extends GeneratedMessage {
             continue outer;
           }
         } else {
-          throw UnsupportedError('Invalid message set item (tag = $tagNumber)');
+          // Skip unknown tags.
+          if (!input.skipField(tag)) {
+            break outer; // End of group.
+          }
         }
       }
     }

diff --git a/protoc_plugin/test/message_set_test.dart b/protoc_plugin/test/message_set_test.dart
@@ -1,6 +1,12 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:fixnum/fixnum.dart';
 import 'package:protobuf/protobuf.dart';
 import 'package:test/test.dart';
 
+import '../out/protos/google/protobuf/empty.pb.dart';
 import '../out/protos/message_set.pb.dart';
 
 void main() {
@@ -45,4 +51,58 @@ void main() {
     expect(extensionValue.b, 'hi');
     expect(msg.unknownFields.isEmpty, true);
   });
+
+  test('Ignore extra item tags', () {
+    // Generate a message set encoding using unknown fields. Message set item
+    // will have extra tags.
+
+    final messageSetUnknownFields = UnknownFieldSet();
+
+    final itemField = UnknownFieldSetField();
+
+    final itemFieldGroup = UnknownFieldSet();
+
+    // Invalid field with tag 1.
+    itemFieldGroup.addField(
+        1, UnknownFieldSetField()..addLengthDelimited([1, 2, 3]));
+
+    // Extension field.
+    itemFieldGroup.addField(
+        3,
+        UnknownFieldSetField()
+          ..addLengthDelimited((ExtensionMessage()
+                ..a = 123456
+                ..b = 'test')
+              .writeToBuffer()));
+
+    // Invalid field with tag 3.
+    itemFieldGroup.addField(
+        4, UnknownFieldSetField()..addVarint(Int64(123456)));
+
+    // Type id field.
+    itemFieldGroup.addField(
+        2, UnknownFieldSetField()..addVarint(Int64(1758024)));
+
+    itemField.addGroup(itemFieldGroup);
+
+    messageSetUnknownFields.addField(1, itemField);
+
+    final messageSetEncoded = CodedBufferWriter();
+    messageSetUnknownFields.writeToCodedBufferWriter(messageSetEncoded);
+
+    final encoded = (Empty()
+          ..unknownFields.addField(
+              123,
+              UnknownFieldSetField()
+                ..lengthDelimited.add(messageSetEncoded.toBuffer())))
+        .writeToBuffer();
+
+    final registry = ExtensionRegistry()..add(TestMessage.messageSetExtension);
+    final msg = TestMessage.fromBuffer(encoded, registry);
+    final extensionValue = msg.info
+        .getExtension(TestMessage.messageSetExtension) as ExtensionMessage;
+    expect(extensionValue.a, 123456);
+    expect(extensionValue.b, 'test');
+    expect(msg.unknownFields.isEmpty, true);
+  });
 }