From a18d6b00510830077a440ebc9ae402018e3c6147 Mon Sep 17 00:00:00 2001
From: Sebastian Zarnekow <Sebastian.Zarnekow@itemis.de>
Date: Tue, 26 Feb 2013 16:09:10 +0100
Subject: [PATCH] [xtext][resource] Improved null contract for ISynchronizable

Change-Id: Ifee0b5e7e94c79879270b92d57aba260b1920411
---
 .../src/org/eclipse/xtext/resource/ISynchronizable.java     | 2 ++
 .../xtext/resource/SynchronizedXtextResourceSet.java        | 6 +++---
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/resource/ISynchronizable.java b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/resource/ISynchronizable.java
index 0e8483370..4e2940877 100644
--- a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/resource/ISynchronizable.java
+++ b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/resource/ISynchronizable.java
@@ -8,6 +8,7 @@
 package org.eclipse.xtext.resource;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.xtext.util.concurrent.IUnitOfWork;
 
 import com.google.common.annotations.Beta;
@@ -34,6 +35,7 @@ public interface ISynchronizable<Synchronizable> {
 	 * @param unit the action to perform. May not be <code>null</code>
 	 * @exception Exception the exception that was thrown by the unit.
 	 */
+	@Nullable
 	<Result> Result execute(IUnitOfWork<Result, ? super Synchronizable> unit) throws Exception;
 	
 }
diff --git a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/resource/SynchronizedXtextResourceSet.java b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/resource/SynchronizedXtextResourceSet.java
index 81c581696..3789701b7 100644
--- a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/resource/SynchronizedXtextResourceSet.java
+++ b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/resource/SynchronizedXtextResourceSet.java
@@ -11,7 +11,7 @@ import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.jdt.annotation.NonNull;
-import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.xtext.util.concurrent.IUnitOfWork;
 
 /**
@@ -54,8 +54,8 @@ public class SynchronizedXtextResourceSet extends XtextResourceSet implements IS
 	 * 
 	 * @since 2.4
 	 */
-	@NonNullByDefault
-	public <Result> Result execute(IUnitOfWork<Result, ? super SynchronizedXtextResourceSet> unit) throws Exception {
+	@Nullable
+	public <Result> Result execute(@NonNull IUnitOfWork<Result, ? super SynchronizedXtextResourceSet> unit) throws Exception {
 		synchronized (getLock()) {
 			return unit.exec(this);
 		}