Don't reset cachedSize to 0 in getSerializedSize

This avoids a race-condition when cachedSize is momentarily set to 0
for non-empty messages if multiple threads call getSerializedSize
(e.g. during serialization).

Change-Id: I15a8ded92edbf41bf1c8d787960c5bbbc8a323c5

1 files changed, 15 insertions, 0 deletions

diff --git a/java/src/test/java/com/google/protobuf/NanoTest.java b/java/src/test/java/com/google/protobuf/NanoTest.java
index 9987cac..4aa6d89 100644
--- a/java/src/test/java/com/google/protobuf/NanoTest.java
+++ b/java/src/test/java/com/google/protobuf/NanoTest.java
@@ -105,6 +105,14 @@ public class NanoTest extends TestCase {
     assertEquals(456, newMsg.d);
     assertEquals(2, msg.nestedMsg.bb);
     assertEquals(SimpleMessageNano.BAR, msg.defaultNestedEnum);
+
+    msg.nestedMsg = null;
+    assertEquals(msgSerializedSize, msg.getCachedSize());
+    assertTrue(msgSerializedSize != msg.getSerializedSize());
+
+    msg.clear();
+    assertEquals(0, msg.getCachedSize());
+    assertEquals(0, msg.getSerializedSize());
   }
 
   public void testRecursiveMessageNano() throws Exception {
@@ -3532,6 +3540,13 @@ public class NanoTest extends TestCase {
     assertTrue(Arrays.equals(new boolean[] {false, true, false, true}, nonPacked.bools));
   }
 
+  public void testMessageNoFields() {
+    SingleMessageNano msg = new SingleMessageNano();
+    assertEquals(0, msg.getSerializedSize());
+    assertEquals(0, msg.getCachedSize());
+    assertEquals(0, MessageNano.toByteArray(msg).length);
+  }
+
   private void assertRepeatedPackablesEqual(
       NanoRepeatedPackables.NonPacked nonPacked, NanoRepeatedPackables.Packed packed) {
     // Not using MessageNano.equals() -- that belongs to a separate test.