Backport of workaround from Eclipse Bug 389754 to Orion v0.5

orion_0_5_deadlock_workaround_backport.diff

diff --git a/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/WebElement.java b/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/WebElement.java
index 652cad7..9aa40ee 100644
--- a/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/WebElement.java
+++ b/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/WebElement.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2010 IBM Corporation and others.
+ * Copyright (c) 2010, 2012 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -59,7 +59,8 @@ public class WebElement {
 	 */
 	public void save() throws CoreException {
 		try {
-			store.flush();
+			//flush directly at root level to workaround equinox bug 389754.
+			store.parent().flush();
 		} catch (BackingStoreException e) {
 			throw new CoreException(new Status(IStatus.ERROR, ServerConstants.PI_SERVER_CORE, "Error saving state"));
 		}
diff --git a/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/WebUser.java b/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/WebUser.java
index 499a117..3363593 100644
--- a/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/WebUser.java
+++ b/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/WebUser.java
@@ -41,12 +41,13 @@ public class WebUser extends WebElement {
 			result.put(ProtocolConstants.KEY_NAME, userName);
 		if (result.get(ProtocolConstants.KEY_ID, null) == null)
 			result.put(ProtocolConstants.KEY_ID, new UniversalUniqueIdentifier().toBase64String());
+		WebUser user = new WebUser(result);
 		try {
-			result.flush();
-		} catch (BackingStoreException e) {
+			user.save();
+		} catch (CoreException e) {
 			LogHelper.log(e);
 		}
-		return new WebUser(result);
+		return user;
 	}
 
 	public WebWorkspace createWorkspace(String name) throws CoreException {
diff --git a/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/authorization/AuthorizationService.java b/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/authorization/AuthorizationService.java
index f01644f..dac391c 100644
--- a/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/authorization/AuthorizationService.java
+++ b/bundles/org.eclipse.orion.server.servlets/src/org/eclipse/orion/internal/server/servlets/workspace/authorization/AuthorizationService.java
@@ -105,7 +105,8 @@ public class AuthorizationService {
 	private static void saveRights(IEclipsePreferences result, JSONArray userRightArray) throws BackingStoreException {
 		result.put(ProtocolConstants.KEY_USER_RIGHTS, userRightArray.toString());
 		result.putInt(ProtocolConstants.KEY_USER_RIGHTS_VERSION, CURRENT_VERSION);
-		result.flush();
+		//flush directly at root level to workaround equinox bug 389754.
+		result.parent().flush();
 	}
 
 	/**
diff --git a/tests/org.eclipse.orion.server.tests/src/org/eclipse/orion/server/tests/prefs/PreferenceTest.java b/tests/org.eclipse.orion.server.tests/src/org/eclipse/orion/server/tests/prefs/PreferenceTest.java
index ce11fb1..2969990 100644
--- a/tests/org.eclipse.orion.server.tests/src/org/eclipse/orion/server/tests/prefs/PreferenceTest.java
+++ b/tests/org.eclipse.orion.server.tests/src/org/eclipse/orion/server/tests/prefs/PreferenceTest.java
@@ -20,6 +20,7 @@ import java.net.URLEncoder;
 import java.util.Arrays;
 import java.util.List;
 
+import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.eclipse.orion.internal.server.core.IOUtilities;
 import org.eclipse.orion.server.core.users.OrionScope;
 import org.eclipse.orion.server.tests.AbstractServerTest;
@@ -45,13 +46,22 @@ public class PreferenceTest extends AbstractServerTest {
 	@Before
 	public void setUp() throws BackingStoreException {
 		OrionScope prefs = new OrionScope();
-		prefs.getNode("Users").removeNode();
-		prefs.getNode("Workspaces").removeNode();
-		prefs.getNode("Projects").removeNode();
+		clearPreferences(prefs.getNode("Users"));
+		clearPreferences(prefs.getNode("Workspaces"));
+		clearPreferences(prefs.getNode("Projects"));
 		webConversation = new WebConversation();
 		webConversation.setExceptionsThrownOnErrorStatus(false);
 	}
 
+	private void clearPreferences(IEclipsePreferences prefs) throws BackingStoreException {
+		//clear  children
+		for (String child : prefs.childrenNames()) {
+			prefs.node(child).removeNode();
+		}
+		prefs.clear();
+		prefs.flush();
+	}
+
 	@Test
 	public void testGetSingle() throws IOException, JSONException {
 		List<String> locations = getTestPreferenceNodes();
@@ -227,21 +237,21 @@ public class PreferenceTest extends AbstractServerTest {
 			WebRequest request = new GetMethodWebRequest(location);
 			setAuthentication(request);
 			WebResponse response = webConversation.getResource(request);
-			assertEquals(HttpURLConnection.HTTP_NOT_FOUND, response.getResponseCode());
+			assertEquals("1." + location, HttpURLConnection.HTTP_NOT_FOUND, response.getResponseCode());
 
 			//put a value
 			request = createSetPreferenceRequest(location, "Name", "Frodo");
 			setAuthentication(request);
 			response = webConversation.getResource(request);
-			assertEquals("1." + location, HttpURLConnection.HTTP_NO_CONTENT, response.getResponseCode());
+			assertEquals("2." + location, HttpURLConnection.HTTP_NO_CONTENT, response.getResponseCode());
 
 			//now doing a get should succeed
 			request = new GetMethodWebRequest(location);
 			setAuthentication(request);
 			response = webConversation.getResource(request);
-			assertEquals("2." + location, HttpURLConnection.HTTP_OK, response.getResponseCode());
+			assertEquals("3." + location, HttpURLConnection.HTTP_OK, response.getResponseCode());
 			JSONObject result = new JSONObject(response.getText());
-			assertEquals("3." + location, "Frodo", result.optString("Name"));
+			assertEquals("4." + location, "Frodo", result.optString("Name"));
 		}
 	}