1 files changed, 90 insertions, 17 deletions
diff --git a/java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java b/java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java
index 4acd8f2f..53af544f 100644
--- a/java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java
@@ -38,6 +38,11 @@ import com.google.protobuf.Descriptors.EnumValueDescriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.Descriptors.FileDescriptor;
 import com.google.protobuf.Descriptors.OneofDescriptor;
+import com.google.protobuf.Internal.BooleanList;
+import com.google.protobuf.Internal.DoubleList;
+import com.google.protobuf.Internal.FloatList;
+import com.google.protobuf.Internal.IntList;
+import com.google.protobuf.Internal.LongList;
 // In opensource protobuf, we have versioned this GeneratedMessageV3 class to GeneratedMessageV3V3 and
 // in the future may have GeneratedMessageV3V4 etc. This allows us to change some aspects of this
 // class without breaking binary compatibility with old generated code that still subclasses
@@ -293,16 +298,17 @@ public abstract class GeneratedMessageV3 extends AbstractMessage
     return unknownFields.mergeFieldFrom(tag, input);
   }
 
+  /**
+   * Delegates to parseUnknownField. This method is obsolete, but we must retain it for
+   * compatibility with older generated code.
+   */
   protected boolean parseUnknownFieldProto3(
       CodedInputStream input,
       UnknownFieldSet.Builder unknownFields,
       ExtensionRegistryLite extensionRegistry,
       int tag)
       throws IOException {
-    if (input.shouldDiscardUnknownFieldsProto3()) {
-      return input.skipField(tag);
-    }
-    return unknownFields.mergeFieldFrom(tag, input);
+    return parseUnknownField(input, unknownFields, extensionRegistry, tag);
   }
 
   protected static <M extends Message> M parseWithIOException(Parser<M> parser, InputStream input)
@@ -363,6 +369,76 @@ public abstract class GeneratedMessageV3 extends AbstractMessage
     return UnsafeUtil.hasUnsafeArrayOperations() && UnsafeUtil.hasUnsafeByteBufferOperations();
   }
 
+  protected static IntList emptyIntList() {
+    return IntArrayList.emptyList();
+  }
+
+  protected static IntList newIntList() {
+    return new IntArrayList();
+  }
+
+  protected static IntList mutableCopy(IntList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static LongList emptyLongList() {
+    return LongArrayList.emptyList();
+  }
+
+  protected static LongList newLongList() {
+    return new LongArrayList();
+  }
+
+  protected static LongList mutableCopy(LongList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static FloatList emptyFloatList() {
+    return FloatArrayList.emptyList();
+  }
+
+  protected static FloatList newFloatList() {
+    return new FloatArrayList();
+  }
+
+  protected static FloatList mutableCopy(FloatList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static DoubleList emptyDoubleList() {
+    return DoubleArrayList.emptyList();
+  }
+
+  protected static DoubleList newDoubleList() {
+    return new DoubleArrayList();
+  }
+
+  protected static DoubleList mutableCopy(DoubleList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
+  protected static BooleanList emptyBooleanList() {
+    return BooleanArrayList.emptyList();
+  }
+
+  protected static BooleanList newBooleanList() {
+    return new BooleanArrayList();
+  }
+
+  protected static BooleanList mutableCopy(BooleanList list) {
+    int size = list.size();
+    return list.mutableCopyWithCapacity(
+        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
+  }
+
   @Override
   public void writeTo(final CodedOutputStream output) throws IOException {
     MessageReflection.writeMessageTo(this, getAllFieldsRaw(), output, false);
@@ -641,13 +717,12 @@ public abstract class GeneratedMessageV3 extends AbstractMessage
       return (BuilderType) this;
     }
 
+    /**
+     * Delegates to setUnknownFields. This method is obsolete, but we must retain it for
+     * compatibility with older generated code.
+     */
     protected BuilderType setUnknownFieldsProto3(final UnknownFieldSet unknownFields) {
-      if (CodedInputStream.getProto3DiscardUnknownFieldsDefault()) {
-        return (BuilderType) this;
-      }
-      this.unknownFields = unknownFields;
-      onChanged();
-      return (BuilderType) this;
+      return setUnknownFields(unknownFields);
     }
 
     @Override
@@ -1009,19 +1084,17 @@ public abstract class GeneratedMessageV3 extends AbstractMessage
           getDescriptorForType(), new MessageReflection.ExtensionAdapter(extensions), tag);
     }
 
+    /**
+     * Delegates to parseUnknownField. This method is obsolete, but we must retain it for
+     * compatibility with older generated code.
+     */
     @Override
     protected boolean parseUnknownFieldProto3(
         CodedInputStream input,
         UnknownFieldSet.Builder unknownFields,
         ExtensionRegistryLite extensionRegistry,
         int tag) throws IOException {
-      return MessageReflection.mergeFieldFrom(
-          input,
-          input.shouldDiscardUnknownFieldsProto3() ? null : unknownFields,
-          extensionRegistry,
-          getDescriptorForType(),
-          new MessageReflection.ExtensionAdapter(extensions),
-          tag);
+      return parseUnknownField(input, unknownFields, extensionRegistry, tag);
     }