Handle unknown fields part of a oneof

protobuf/CHANGELOG.md

@@ -1,5 +1,10 @@
 ## 1.0.2
 
+* Fixed generic handling of unknown fields.
+  * `GeneratedMessage.clearField(tagNumber)` will now also clear an unknown
+    field.
+  * `GeneratedMessage.hasField(tagNumber)` will now return true if there is an
+  unknown field.
 * Handle cases where a field that is part of a oneof is removed by the
   protobuf aware treeshaker.
 

protobuf/lib/src/protobuf/extension_field_set.dart

@@ -21,7 +21,10 @@ class _ExtensionFieldSet {
     // I think this was originally here for repeated extensions.
     _addInfoUnchecked(fi);
     var value = _getFieldOrNull(fi);
-    if (value == null) return fi.makeDefault();
+    if (value == null) {
+      _checkNotInUnknown(fi);
+      return fi.makeDefault();
+    }
     return value;
   }
 
@@ -50,6 +53,7 @@ class _ExtensionFieldSet {
   List<T> _getList<T>(Extension<T> fi) {
     var value = _values[fi.tagNumber];
     if (value != null) return value as List<T>;
+    _checkNotInUnknown(fi);
     if (_isReadOnly) return List<T>.unmodifiable(const []);
     return _addInfoAndCreateList(fi);
   }
@@ -184,4 +188,14 @@ class _ExtensionFieldSet {
       }
     }
   }
+
+  void _checkNotInUnknown(Extension extension) {
+    if (_parent._hasUnknownFields &&
+        _parent._unknownFields.hasField(extension.tagNumber)) {
+      throw StateError(
+          'Trying to get $extension that is present as an unknown field. '
+          'Parse the message with this extension in the extension registry or use '
+          '`ExtensionRegistry.reparseMessage`.');
+    }
+  }
 }

protobuf/lib/src/protobuf/field_set.dart

@@ -236,6 +236,9 @@ class _FieldSet {
   bool _hasField(int tagNumber) {
     var fi = _nonExtensionInfo(tagNumber);
     if (fi != null) return _$has(fi.index);
+    if (_hasUnknownFields && _unknownFields.hasField(tagNumber)) {
+      return true;
+    }
     if (!_hasExtensions) return false;
     return _extensions._hasField(tagNumber);
   }
@@ -346,7 +349,8 @@ class _FieldSet {
   void _updateOneOfCase(int newTagnumber) {
     int oneofIndex = _meta.oneofs[newTagnumber];
     if (oneofIndex != null) {
-      _clearField(_oneofCases[oneofIndex]);
+      final currentTagnumber = _oneofCases[oneofIndex];
+      if (currentTagnumber != null) _clearField(currentTagnumber);
       _oneofCases[oneofIndex] = newTagnumber;
     }
   }

protobuf/lib/src/protobuf/generated_message.dart

@@ -358,6 +358,8 @@ abstract class GeneratedMessage {
       _fieldSet._extensions._getFieldOrNull(extension) != null;
 
   /// Returns [:true:] if this message has a field associated with [tagNumber].
+  ///
+  /// Will return [:true:] even if that field is an unknown field.
   bool hasField(int tagNumber) => _fieldSet._hasField(tagNumber);
 
   /// Merges the contents of the [other] into this message.

protoc_plugin/test/oneof_test.dart

@@ -183,6 +183,14 @@ void main() {
     expect(foo.hasIndex(), true);
     expect(foo.index, Bar());
   });
+
+  test('clone', () {
+    Foo foo = Foo()..first = 'oneof';
+    expectFirstSet(foo);
+
+    final foo2 = Foo()..mergeFromMessage(foo);
+    expectFirstSet(foo2);
+  });
 }
 
 void expectSecondSet(Foo foo) {

protoc_plugin/test/unknown_field_set_test.dart

@@ -330,4 +330,9 @@ void main() {
 
     _checkNotEqual(f1, f2);
   });
+
+  test('GeneratedMessage.hasField sees unknown fields', () {
+    expect(emptyMessage.hasField(testAllTypes.getTagNumber('optionalInt32')),
+        true);
+  });
 }