Reparse unknown features using extension registry containing Java fea…

…tures.

This should not be needed for generated code, but may be needed for user calls to the public buildFrom method. FileDescriptorProto should really be parsed with java features in the extension registry (like other extensions), but we can handle this in Java runtime to ease editions adoption.

PiperOrigin-RevId: 638715579

java/core/src/main/java/com/google/protobuf/Descriptors.java

@@ -2782,6 +2782,21 @@ private GenericDescriptor() {}
     public abstract FileDescriptor getFile();
 
     void resolveFeatures(FeatureSet unresolvedFeatures) throws DescriptorValidationException {
+      // Unknown java features may be passed by users via public buildFrom but should not occur from
+      // generated code.
+      if (!unresolvedFeatures.getUnknownFields().isEmpty()
+          && unresolvedFeatures.getUnknownFields().hasField(JavaFeaturesProto.java_.getNumber())) {
+        ExtensionRegistry registry = ExtensionRegistry.newInstance();
+        registry.add(JavaFeaturesProto.java_);
+        ByteString bytes = unresolvedFeatures.toByteString();
+        try {
+          unresolvedFeatures = FeatureSet.parseFrom(bytes, registry);
+        } catch (InvalidProtocolBufferException e) {
+          throw new DescriptorValidationException(
+              this, "Failed to parse features with Java feature extension registry.", e);
+        }
+      }
+
       if (this.parent != null
           && unresolvedFeatures.equals(FeatureSet.getDefaultInstance())
           && !hasInferredLegacyProtoFeatures()) {

java/core/src/test/java/com/google/protobuf/DescriptorsTest.java

@@ -352,7 +352,7 @@ public void testFieldDescriptorDefault() throws Exception {
     }
 
     @Test
-    public void testFieldDescriptorLegacyEnumFieldTreatedAsClosed() throws Exception {
+    public void testProto2FieldDescriptorLegacyEnumFieldTreatedAsClosed() throws Exception {
       // Make an open enum definition.
       FileDescriptorProto openEnumFile =
           FileDescriptorProto.newBuilder()
@@ -430,6 +430,111 @@ public void testFieldDescriptorLegacyEnumFieldTreatedAsClosed() throws Exception
           .isTrue();
     }
 
+    @Test
+    public void testEditionFieldDescriptorLegacyEnumFieldTreatedAsClosed() throws Exception {
+      // Make an open enum definition.
+      FileDescriptorProto openEnumFile =
+          FileDescriptorProto.newBuilder()
+              .setName("open_enum.proto")
+              .setSyntax("editions")
+              .setEdition(Edition.EDITION_2023)
+              .addEnumType(
+                  EnumDescriptorProto.newBuilder()
+                      .setName("TestEnumOpen")
+                      .addValue(
+                          EnumValueDescriptorProto.newBuilder()
+                              .setName("TestEnumOpen_VALUE0")
+                              .setNumber(0)
+                              .build())
+                      .build())
+              .build();
+      FileDescriptor openFileDescriptor =
+          Descriptors.FileDescriptor.buildFrom(openEnumFile, new FileDescriptor[0]);
+      EnumDescriptor openEnum = openFileDescriptor.getEnumTypes().get(0);
+      assertThat(openEnum.isClosed()).isFalse();
+
+      // Create a message that treats enum fields as closed.
+      FileDescriptorProto editionsClosedEnumFile =
+          FileDescriptorProto.newBuilder()
+              .setName("editions_closed_enum_field.proto")
+              .addDependency("open_enum.proto")
+              .setSyntax("editions")
+              .setEdition(Edition.EDITION_2023)
+              .setOptions(
+                  FileOptions.newBuilder()
+                      .setFeatures(
+                          DescriptorProtos.FeatureSet.newBuilder()
+                              .setEnumType(DescriptorProtos.FeatureSet.EnumType.CLOSED)
+                              .build())
+                      .build())
+              .addEnumType(
+                  EnumDescriptorProto.newBuilder()
+                      .setName("TestEnum")
+                      .addValue(
+                          EnumValueDescriptorProto.newBuilder()
+                              .setName("TestEnum_VALUE0")
+                              .setNumber(0)
+                              .build())
+                      .build())
+              .addMessageType(
+                  DescriptorProto.newBuilder()
+                      .setName("TestClosedEnumField")
+                      .addField(
+                          FieldDescriptorProto.newBuilder()
+                              .setName("int_field")
+                              .setNumber(1)
+                              .setType(FieldDescriptorProto.Type.TYPE_INT32)
+                              .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
+                              .build())
+                      .addField(
+                          FieldDescriptorProto.newBuilder()
+                              .setName("open_enum")
+                              .setNumber(2)
+                              .setType(FieldDescriptorProto.Type.TYPE_ENUM)
+                              .setTypeName("TestEnumOpen")
+                              .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
+                              .setOptions(
+                                  DescriptorProtos.FieldOptions.newBuilder()
+                                      .setFeatures(
+                                          DescriptorProtos.FeatureSet.newBuilder()
+                                              .setExtension(
+                                                  JavaFeaturesProto.java_,
+                                                  JavaFeaturesProto.JavaFeatures.newBuilder()
+                                                      .setLegacyClosedEnum(true)
+                                                      .build())
+                                              .build())
+                                      .build())
+                              .build())
+                      .addField(
+                          FieldDescriptorProto.newBuilder()
+                              .setName("closed_enum")
+                              .setNumber(3)
+                              .setType(FieldDescriptorProto.Type.TYPE_ENUM)
+                              .setTypeName("TestEnum")
+                              .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
+                              .build())
+                      .build())
+              .build();
+      // Ensure Java features are in unknown fields.
+      editionsClosedEnumFile =
+          FileDescriptorProto.parseFrom(
+              editionsClosedEnumFile.toByteString(), ExtensionRegistry.getEmptyRegistry());
+      Descriptor editionsClosedMessage =
+          Descriptors.FileDescriptor.buildFrom(
+                  editionsClosedEnumFile, new FileDescriptor[] {openFileDescriptor})
+              .getMessageTypes()
+              .get(0);
+      assertThat(
+              editionsClosedMessage.findFieldByName("int_field").legacyEnumFieldTreatedAsClosed())
+          .isFalse();
+      assertThat(
+              editionsClosedMessage.findFieldByName("closed_enum").legacyEnumFieldTreatedAsClosed())
+          .isTrue();
+      assertThat(
+              editionsClosedMessage.findFieldByName("open_enum").legacyEnumFieldTreatedAsClosed())
+          .isTrue();
+    }
+
     @Test
     public void testFieldDescriptorLegacyEnumFieldTreatedAsOpen() throws Exception {
       // Make an open enum definition and message that treats enum fields as open.