Index: DESCRIPTION
===================================================================
--- DESCRIPTION	(revision 453)
+++ DESCRIPTION	(working copy)
@@ -1,5 +1,5 @@
 Package: RProtoBuf
-Version: 0.2.4
+Version: 0.2.5
 Date: $Date$
 Author: Romain Francois <romain@r-enthusiasts.com> and Dirk Eddelbuettel <edd@debian.org>
 Maintainer: Romain and Dirk <RomainAndDirk@r-enthusiasts.com>
Index: src/mutators.cpp
===================================================================
--- src/mutators.cpp	(revision 453)
+++ src/mutators.cpp	(working copy)
@@ -367,7 +367,7 @@
 	
 	const Reflection * ref = message->GetReflection() ;
     
-	if( value == R_NilValue || LENGTH(value) == 0 ){
+	if( value == R_NilValue || (Rf_isVector(value) && LENGTH(value) == 0 )) {
 		ref->ClearField( message, field_desc ); 
 		return R_NilValue ;
 	}
Index: inst/unitTests/runit.nested.R
===================================================================
--- inst/unitTests/runit.nested.R	(revision 0)
+++ inst/unitTests/runit.nested.R	(revision 0)
@@ -0,0 +1,16 @@
+.setUp <- function(){
+    if( ! exists( "NestedOuter", "RProtoBuf:DescriptorPool" ) ) {
+        # None of the messages in unittest.proto is exactly right to tickle this bug.
+        unitest.proto.file <- system.file( "unitTests", "data", "nested.proto", package = "RProtoBuf" )
+        readProtoFiles(file = unitest.proto.file)
+    }
+}
+
+# RProtoBuf before v0.2.5 had a bug whereby uninitialized memory was read and used
+# to determine whether or not to update a nested message field in new() / update().
+test.nested <- function() {
+  for (i in 1:1000) {
+    q <- new(NestedOuter, b=new(NestedInner, x=1))
+    checkTrue(q$isInitialized())
+  }
+}
Index: inst/unitTests/data/nested.proto
===================================================================
--- inst/unitTests/data/nested.proto	(revision 0)
+++ inst/unitTests/data/nested.proto	(revision 0)
@@ -0,0 +1,6 @@
+message NestedInner {
+  required int32 x = 1;
+}
+message NestedOuter {
+  required NestedInner b = 1;
+}