Bug 280262 NPE in editors in closed projects => user friendly error message

createProjectDescription throws a CoreException as defined by the API rather than returning null when the project is inaccessible.

core/org.eclipse.cdt.core.tests/model/org/eclipse/cdt/core/settings/model/CProjectDescriptionBasicTests.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007 Intel Corporation and others.
+ * Copyright (c) 2007, 2010 Intel 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
@@ -127,6 +127,28 @@ public class CProjectDescriptionBasicTests  extends BaseTestCase{
 
 	}
 
+	public void testCreateProjectDescriptionInvalidProject() throws Exception {
+		IProject project = ResourcesPlugin.getWorkspace().getRoot().getProject("someProject");
+		assertTrue(!project.isAccessible());
+
+		ICProjectDescriptionManager mngr = CoreModel.getDefault().getProjectDescriptionManager();
+		boolean exception = false;
+		try {
+			mngr.createProjectDescription(null, false, true);
+		} catch (CoreException e) {
+			exception = true;
+		}
+		assertTrue(exception);
+
+		exception = false;
+		try {
+			mngr.createProjectDescription(project, false, true);
+		} catch (CoreException e) {
+			exception = true;
+		}
+		assertTrue(exception);
+	}
+
 	public void testSetInvalidCreatingDescription() throws Exception {
 		IWorkspace wsp = ResourcesPlugin.getWorkspace();
 		IWorkspaceRoot root = wsp.getRoot();

core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/settings/model/ICProjectDescriptionManager.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2008 Intel Corporation and others.
+ * Copyright (c) 2007, 2010 Intel 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
@@ -73,6 +73,7 @@ public interface ICProjectDescriptionManager {
 	 * and returns a writable project description which is either empty or a copy of the previous configuration description
 	 * if loadIfExists == true.
 	 * @see #createProjectDescription(IProject, boolean, boolean)
+ 	 * @throws CoreException if the Project doesn't exist, or the storage couldn't be found
 	 */
 	ICProjectDescription createProjectDescription(IProject project, boolean loadIfExists) throws CoreException;
 
@@ -89,7 +90,7 @@ public interface ICProjectDescriptionManager {
 	 *
 	 * NOTE: changes made to the returned project description will not be applied until the {@link #setProjectDescription(IProject, ICProjectDescription)} is called
 	 * @return {@link ICProjectDescription}
-	 * @throws CoreException
+	 * @throws CoreException if the Project doesn't exist, or the storage couldn't be found
 	 */
 	ICProjectDescription createProjectDescription(IProject project, boolean loadIfExists, boolean creating) throws CoreException;
 

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/CProjectDescriptionManager.java

@@ -390,19 +390,28 @@ public class CProjectDescriptionManager implements ICProjectDescriptionManager {
 	}
 
 	public ICProjectDescription getProjectDescription(IProject project, int flags) {
-		AbstractCProjectDescriptionStorage storage = getProjectDescriptionStorage(project);
+		try {
-		if (storage != null) {
+			return getProjectDescriptionInternal(project, flags);
-			try {
+		} catch (CoreException e) {
-				return storage.getProjectDescription(flags, new NullProgressMonitor());
+			// FIXME Currently the resource change handler ResourceChangeHandler.getProjectDescription(...)
-			} catch (CoreException e) {
+			// Does this when the project is closed. Don't log an error or the tests will fail
-				// FIXME Currently the resource change handler ResourceChangeHandler.getProjectDescription(...)
-				// Does this when the project is closed. Don't log an error or the tests will fail
 //				CCorePlugin.log(e);
-			}
 		}
 		return null;
 	}
 
+	/**
+	 * Base method for getting a Project's Description 
+	 * @param project
+	 * @param flags
+	 * @return ICProjectDescription
+	 * @throws CoreException if project description isn't available
+	 */
+	private ICProjectDescription getProjectDescriptionInternal(IProject project, int flags) throws CoreException {
+		AbstractCProjectDescriptionStorage storage = getProjectDescriptionStorage(project);
+		return storage.getProjectDescription(flags, new NullProgressMonitor());
+	}	
+
 	/**
 	 * Run the workspace modification in the current thread using the workspace scheduling rule
 	 * Equivalent to: <code>runWspModification(IWorkspaceRunnable, ResourcecPlugin.getWorkspace().getRoot(), IProgressMonitor)</code>
@@ -587,7 +596,7 @@ public class CProjectDescriptionManager implements ICProjectDescriptionManager {
 		flags |= loadIfExists ? 0 : ICProjectDescriptionManager.GET_EMPTY_PROJECT_DESCRIPTION;
 		flags |= creating ? ICProjectDescriptionManager.PROJECT_CREATING : 0;
 
-		return getProjectDescription(project, flags);
+		return getProjectDescriptionInternal(project, flags);
 	}
 
 	public ScannerInfoProviderProxy getScannerInfoProviderProxy(IProject project){
@@ -816,8 +825,19 @@ public class CProjectDescriptionManager implements ICProjectDescriptionManager {
 		return settingProjectDescription.get();
 	}
 
-	private AbstractCProjectDescriptionStorage getProjectDescriptionStorage(IProject project) {
+	/**
-		return CProjectDescriptionStorageManager.getInstance().getProjectDescriptionStorage(project);
+	 * Base for getting a project desc's storage. project must be accessible.
+	 * @param project
+	 * @return ProjectDescription storage
+	 * @throws CoreException if Project isn't accessible
+	 */
+	private AbstractCProjectDescriptionStorage getProjectDescriptionStorage(IProject project) throws CoreException {
+		if (project == null || !project.isAccessible())
+			throw ExceptionFactory.createCoreException(MessageFormat.format(CCorePlugin.getResourceString("ProjectDescription.ProjectNotAccessible"), new Object[] {project != null ? project.getName() : "<null>"})); //$NON-NLS-1$ //$NON-NLS-2$
+		AbstractCProjectDescriptionStorage storage = CProjectDescriptionStorageManager.getInstance().getProjectDescriptionStorage(project);
+		if (storage == null)
+			throw ExceptionFactory.createCoreException(SettingsModelMessages.getString("CProjectDescriptionManager.FailedToGetStorage") + project.getName()); //$NON-NLS-1$
+		return storage;
 	}
 
 	/**

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/SettingsModelMessages.properties

@@ -31,13 +31,14 @@ CProjectDescriptionManager.9=invalid project file format
 CProjectDescriptionManager.0=Initiating resource change handling..
 CProjectDescriptionManager.10=invalid project file format
 CProjectDescriptionManager.11=storage file not found
-CProjectDescriptionManager.12=Serialing CDT Project settings.. 
+CProjectDescriptionManager.12=Serializing CDT Project settings.. 
 CProjectDescriptionManager.13=Refreshing the project settings
 CProjectDescriptionManager.14=workspace info element does not exist
 CProjectDescriptionManager.15=Preference Configuration
 CProjectDescriptionManager.16=attempt to set description for the non-openned project
 CProjectDescriptionManager.17=unable to apply the invalid project description for project 
 CProjectDescriptionManager.cfgIDAlreadyExists=Configuration with ID: {0} already exists in passed in settings storage
+CProjectDescriptionManager.FailedToGetStorage=Failed to get storage for project: 
 CProjectDescriptionManager.illegalDeltaKind=Illegal delta kind 
 CProjectDescriptionManager.wrongTypeOfResourceDescription=Wrong type of resource description: 
 CFolderDescription.0=data was not created