Merge from google internal

9 files changed, 91 insertions, 48 deletions

diff --git a/java/core/src/main/java/com/google/protobuf/AbstractMessage.java b/java/core/src/main/java/com/google/protobuf/AbstractMessage.java
index 065fa1a9..908764df 100644
--- a/java/core/src/main/java/com/google/protobuf/AbstractMessage.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractMessage.java
@@ -380,6 +380,10 @@ public abstract class AbstractMessage
 
     @Override
     public BuilderType mergeFrom(final Message other) {
+      return mergeFrom(other, other.getAllFields());
+    }
+    
+    BuilderType mergeFrom(final Message other, Map<FieldDescriptor, Object> allFields) {
       if (other.getDescriptorForType() != getDescriptorForType()) {
         throw new IllegalArgumentException(
           "mergeFrom(Message) can only merge messages of the same type.");
@@ -394,8 +398,7 @@ public abstract class AbstractMessage
       // TODO(kenton):  Provide a function somewhere called makeDeepCopy()
       //   which allows people to make secure deep copies of messages.
 
-      for (final Map.Entry<FieldDescriptor, Object> entry :
-           other.getAllFields().entrySet()) {
+      for (final Map.Entry<FieldDescriptor, Object> entry : allFields.entrySet()) {
         final FieldDescriptor field = entry.getKey();
         if (field.isRepeated()) {
           for (final Object element : (List)entry.getValue()) {
diff --git a/java/core/src/main/java/com/google/protobuf/CodedInputStream.java b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
index 511501d4..e08a993b 100644
--- a/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
+++ b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
@@ -413,8 +413,7 @@ public abstract class CodedInputStream {
 
   private boolean explicitDiscardUnknownFields = false;
 
-  /** TODO(liujisi): flip the default.*/
-  private static volatile boolean proto3DiscardUnknownFieldsDefault = true;
+  private static volatile boolean proto3DiscardUnknownFieldsDefault = false;
 
   static void setProto3DiscardUnknownsByDefaultForTest() {
     proto3DiscardUnknownFieldsDefault = true;
diff --git a/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
index 99864964..09084646 100644
--- a/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
@@ -31,7 +31,6 @@
 package com.google.protobuf;
 
 import com.google.protobuf.AbstractMessageLite.Builder.LimitedInputStream;
-import com.google.protobuf.GeneratedMessageLite.EqualsVisitor.NotEqualsException;
 import com.google.protobuf.Internal.BooleanList;
 import com.google.protobuf.Internal.DoubleList;
 import com.google.protobuf.Internal.EnumLiteMap;
@@ -52,6 +51,7 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * Lite version of {@link GeneratedMessage}.
@@ -62,6 +62,12 @@ public abstract class GeneratedMessageLite<
     MessageType extends GeneratedMessageLite<MessageType, BuilderType>,
     BuilderType extends GeneratedMessageLite.Builder<MessageType, BuilderType>>
         extends AbstractMessageLite<MessageType, BuilderType> {
+  // BEGIN REGULAR
+  static final boolean ENABLE_EXPERIMENTAL_RUNTIME_AT_BUILD_TIME = false;
+  // END REGULAR
+  // BEGIN EXPERIMENTAL
+  // static final boolean ENABLE_EXPERIMENTAL_RUNTIME_AT_BUILD_TIME = true;
+  // END EXPERIMENTAL
 
   /** For use by generated code only. Lazily initialized to reduce allocations. */
   protected UnknownFieldSetLite unknownFields = UnknownFieldSetLite.getDefaultInstance();
@@ -110,12 +116,19 @@ public abstract class GeneratedMessageLite<
     if (memoizedHashCode != 0) {
       return memoizedHashCode;
     }
+    // BEGIN EXPERIMENTAL
+    // memoizedHashCode = Protobuf.getInstance().schemaFor(this).hashCode(this);
+    // return memoizedHashCode;
+    // END EXPERIMENTAL
+    // BEGIN REGULAR
     HashCodeVisitor visitor = new HashCodeVisitor();
     visit(visitor, (MessageType) this);
     memoizedHashCode = visitor.hashCode;
     return memoizedHashCode;
+    // END REGULAR
   }
 
+  // BEGIN REGULAR
   @SuppressWarnings("unchecked") // Guaranteed by runtime
   int hashCode(HashCodeVisitor visitor) {
     if (memoizedHashCode == 0) {
@@ -127,6 +140,7 @@ public abstract class GeneratedMessageLite<
     }
     return memoizedHashCode;
   }
+  // END REGULAR
 
   @SuppressWarnings("unchecked") // Guaranteed by isInstance + runtime
   @Override
@@ -139,18 +153,22 @@ public abstract class GeneratedMessageLite<
       return false;
     }
 
+    // BEGIN EXPERIMENTAL
+    // return Protobuf.getInstance().schemaFor(this).equals(this, (MessageType) other);
+    // END EXPERIMENTAL
+    // BEGIN REGULAR
 
     try {
       visit(EqualsVisitor.INSTANCE, (MessageType) other);
-    } catch (NotEqualsException e) {
+    } catch (EqualsVisitor.NotEqualsException e) {
       return false;
     }
     return true;
+    // END REGULAR
   }
 
-  /**
-   * Same as {@link #equals(Object)} but throws {@code NotEqualsException}.
-   */
+  // BEGIN REGULAR
+  /** Same as {@link #equals(Object)} but throws {@code NotEqualsException}. */
   @SuppressWarnings("unchecked") // Guaranteed by isInstance + runtime
   boolean equals(EqualsVisitor visitor, MessageLite other) {
     if (this == other) {
@@ -164,14 +182,13 @@ public abstract class GeneratedMessageLite<
     visit(visitor, (MessageType) other);
     return true;
   }
+  // END REGULAR
 
   // The general strategy for unknown fields is to use an UnknownFieldSetLite that is treated as
   // mutable during the parsing constructor and immutable after. This allows us to avoid
   // any unnecessary intermediary allocations while reducing the generated code size.
 
-  /**
-   * Lazily initializes unknown fields.
-   */
+  /** Lazily initializes unknown fields. */
   private final void ensureUnknownFieldsInitialized() {
     if (unknownFields == UnknownFieldSetLite.getDefaultInstance()) {
       unknownFields = UnknownFieldSetLite.newInstance();
@@ -218,6 +235,20 @@ public abstract class GeneratedMessageLite<
     unknownFields.makeImmutable();
   }
 
+  protected final <
+    MessageType extends GeneratedMessageLite<MessageType, BuilderType>,
+    BuilderType extends GeneratedMessageLite.Builder<MessageType, BuilderType>>
+        BuilderType createBuilder() {
+    return (BuilderType) dynamicMethod(MethodToInvoke.NEW_BUILDER);
+  }
+
+  protected final <
+    MessageType extends GeneratedMessageLite<MessageType, BuilderType>,
+    BuilderType extends GeneratedMessageLite.Builder<MessageType, BuilderType>>
+        BuilderType createBuilder(MessageType prototype) {
+    return ((BuilderType) createBuilder()).mergeFrom(prototype);
+  }
+
   @Override
   public final boolean isInitialized() {
     return isInitialized((MessageType) this, Boolean.TRUE);
@@ -238,11 +269,13 @@ public abstract class GeneratedMessageLite<
    * For use by generated code only.
    */
   public static enum MethodToInvoke {
-    // Rely on/modify instance state
     IS_INITIALIZED,
+    // BEGIN REGULAR
+    VISIT,
+    // END REGULAR
+    // Rely on/modify instance state
     GET_MEMOIZED_IS_INITIALIZED,
     SET_MEMOIZED_IS_INITIALIZED,
-    VISIT,
     MERGE_FROM_STREAM,
     MAKE_IMMUTABLE,
 
@@ -299,10 +332,13 @@ public abstract class GeneratedMessageLite<
     return dynamicMethod(method, null, null);
   }
 
+  // BEGIN REGULAR
   void visit(Visitor visitor, MessageType other) {
     dynamicMethod(MethodToInvoke.VISIT, visitor, other);
     unknownFields = visitor.visitUnknownFields(unknownFields, other.unknownFields);
   }
+  // END REGULAR
+
 
 
   /**
@@ -399,7 +435,12 @@ public abstract class GeneratedMessageLite<
     }
 
     private void mergeFromInstance(MessageType dest, MessageType src) {
+      // BEGIN EXPERIMENTAL
+      // Protobuf.getInstance().schemaFor(dest).mergeFrom(dest, src);
+      // END EXPERIMENTAL
+      // BEGIN REGULAR
       dest.visit(MergeFromVisitor.INSTANCE, src);
+      // END REGULAR
     }
 
     @Override
@@ -477,11 +518,13 @@ public abstract class GeneratedMessageLite<
       extensions.mergeFrom(((ExtendableMessage) other).extensions);
     }
 
+    // BEGIN REGULAR
     @Override
     final void visit(Visitor visitor, MessageType other) {
       super.visit(visitor, other);
       extensions = visitor.visitExtensions(extensions, other.extensions);
     }
+    // END REGULAR
 
     /**
      * Parse an unknown field or an extension. For use by generated code only.
@@ -494,7 +537,8 @@ public abstract class GeneratedMessageLite<
         MessageType defaultInstance,
         CodedInputStream input,
         ExtensionRegistryLite extensionRegistry,
-        int tag) throws IOException {
+        int tag)
+        throws IOException {
       int fieldNumber = WireFormat.getTagFieldNumber(tag);
 
       // TODO(dweis): How much bytecode would be saved by not requiring the generated code to
@@ -1716,6 +1760,7 @@ public abstract class GeneratedMessageLite<
     return message;
   }
 
+  // BEGIN REGULAR
   /**
    * An abstract visitor that the generated code calls into that we use to implement various
    * features. Fields that are not members of oneofs are always visited. Members of a oneof are only
@@ -2401,4 +2446,5 @@ public abstract class GeneratedMessageLite<
       return mine;
     }
   }
+  // END REGULAR
 }
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 592869a1..4acd8f2f 100644
--- a/java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java
@@ -358,6 +358,10 @@ public abstract class GeneratedMessageV3 extends AbstractMessage
       throw e.unwrapIOException();
     }
   }
+  
+  protected static boolean canUseUnsafe() {
+    return UnsafeUtil.hasUnsafeArrayOperations() && UnsafeUtil.hasUnsafeByteBufferOperations();
+  }
 
   @Override
   public void writeTo(final CodedOutputStream output) throws IOException {
@@ -655,6 +659,7 @@ public abstract class GeneratedMessageV3 extends AbstractMessage
                        .build());
     }
 
+
     @Override
     public boolean isInitialized() {
       for (final FieldDescriptor field : getDescriptorForType().getFields()) {
@@ -2853,3 +2858,4 @@ public abstract class GeneratedMessageV3 extends AbstractMessage
     }
   }
 }
+
diff --git a/java/core/src/main/java/com/google/protobuf/Message.java b/java/core/src/main/java/com/google/protobuf/Message.java
index 94590fb9..0770d417 100644
--- a/java/core/src/main/java/com/google/protobuf/Message.java
+++ b/java/core/src/main/java/com/google/protobuf/Message.java
@@ -125,7 +125,7 @@ public interface Message extends MessageLite, MessageOrBuilder {
      *   it is merged into the corresponding sub-message of this message
      *   using the same merging rules.<br>
      * * For repeated fields, the elements in {@code other} are concatenated
-     *   with the elements in this message.
+     *   with the elements in this message.<br>
      * * For oneof groups, if the other message has one of the fields set,
      *   the group of this message is cleared and replaced by the field
      *   of the other message, so that the oneof constraint is preserved.
diff --git a/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java b/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
index ff686a0c..42da5bb3 100644
--- a/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
+++ b/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
@@ -404,34 +404,4 @@ public class FieldPresenceTest extends TestCase {
     assertTrue(builder.buildPartial().isInitialized());
   }
 
-
-  // Test that unknown fields are dropped.
-  public void testUnknownFields() throws Exception {
-    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
-    builder.setOptionalInt32(1234);
-    builder.addRepeatedInt32(5678);
-    TestAllTypes message = builder.build();
-    ByteString data = message.toByteString();
-
-    TestOptionalFieldsOnly optionalOnlyMessage =
-        TestOptionalFieldsOnly.parseFrom(data);
-    // UnknownFieldSet should be empty.
-    assertEquals(
-        0, optionalOnlyMessage.getUnknownFields().toByteString().size());
-    assertEquals(1234, optionalOnlyMessage.getOptionalInt32());
-    message = TestAllTypes.parseFrom(optionalOnlyMessage.toByteString());
-    assertEquals(1234, message.getOptionalInt32());
-    // The repeated field is discarded because it's unknown to the optional-only
-    // message.
-    assertEquals(0, message.getRepeatedInt32Count());
-
-    DynamicMessage dynamicOptionalOnlyMessage =
-        DynamicMessage.getDefaultInstance(
-            TestOptionalFieldsOnly.getDescriptor())
-        .getParserForType().parseFrom(data);
-    assertEquals(
-        0, dynamicOptionalOnlyMessage.getUnknownFields().toByteString().size());
-    assertEquals(optionalOnlyMessage.toByteString(),
-        dynamicOptionalOnlyMessage.toByteString());
-  }
 }
diff --git a/java/core/src/test/java/com/google/protobuf/LiteTest.java b/java/core/src/test/java/com/google/protobuf/LiteTest.java
index ba4d539d..40b44538 100644
--- a/java/core/src/test/java/com/google/protobuf/LiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LiteTest.java
@@ -1453,6 +1453,15 @@ public class LiteTest extends TestCase {
             UnittestLite.optionalFixed32ExtensionLite));
   }
 
+  public void testBuilderMergeFromNull() throws Exception {
+    try {
+      TestAllTypesLite.newBuilder().mergeFrom((TestAllTypesLite) null);
+      fail("Expected exception");
+    } catch (NullPointerException e) {
+      // Pass.
+    }
+  }
+
   // Builder.mergeFrom() should keep existing extensions.
   public void testBuilderMergeFromWithExtensions() throws Exception {
     TestAllExtensionsLite message =
diff --git a/java/util/src/main/java/com/google/protobuf/util/FieldMaskTree.java b/java/util/src/main/java/com/google/protobuf/util/FieldMaskTree.java
index b192b53e..e017b987 100644
--- a/java/util/src/main/java/com/google/protobuf/util/FieldMaskTree.java
+++ b/java/util/src/main/java/com/google/protobuf/util/FieldMaskTree.java
@@ -34,7 +34,6 @@ import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.FieldMask;
 import com.google.protobuf.Message;
-
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map.Entry;
@@ -244,6 +243,11 @@ final class FieldMaskTree {
                   + "singluar message field and cannot have sub-fields.");
           continue;
         }
+        if (!source.hasField(field) && !destination.hasField(field)) {
+          // If the message field is not present in both source and destination, skip recursing
+          // so we don't create unneccessary empty messages.
+          continue;
+        }
         String childPath = path.isEmpty() ? entry.getKey() : path + "." + entry.getKey();
         merge(
             entry.getValue(),
diff --git a/java/util/src/test/java/com/google/protobuf/util/FieldMaskTreeTest.java b/java/util/src/test/java/com/google/protobuf/util/FieldMaskTreeTest.java
index 3ee0fc6e..853b6151 100644
--- a/java/util/src/test/java/com/google/protobuf/util/FieldMaskTreeTest.java
+++ b/java/util/src/test/java/com/google/protobuf/util/FieldMaskTreeTest.java
@@ -33,7 +33,6 @@ package com.google.protobuf.util;
 import protobuf_unittest.UnittestProto.NestedTestAllTypes;
 import protobuf_unittest.UnittestProto.TestAllTypes;
 import protobuf_unittest.UnittestProto.TestAllTypes.NestedMessage;
-
 import junit.framework.TestCase;
 
 public class FieldMaskTreeTest extends TestCase {
@@ -222,6 +221,13 @@ public class FieldMaskTreeTest extends TestCase {
     new FieldMaskTree().addFieldPath("payload").merge(clearedSource, builder, options);
     assertEquals(false, builder.hasPayload());
 
+    // Skip a message field if they are unset in both source and target.
+    builder = NestedTestAllTypes.newBuilder();
+    new FieldMaskTree()
+        .addFieldPath("payload.optional_int32")
+        .merge(clearedSource, builder, options);
+    assertEquals(false, builder.hasPayload());
+
     // Change to replace message fields.
     options.setReplaceMessageFields(true);
     builder = NestedTestAllTypes.newBuilder();