Bug 125144 Clicking Show Project in Package Explorer results in exception
Clicking Show Project in Code model results in exception in DOS box === Steps to Reproduce: Create a Java project Open the Package Explorer Click the View menu Show - Projects. (This actually is a radio group menu item. It is by default selected, so clicking it again should have no effect) === Observed behaviour: Dos box: Unhandled event loop exception Reason: java.lang.NullPointerException See .log file (will be attached) === Expected behaviour: No exception === Reproducibility: yes
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
* 
	 * @since 2.1
	 */
	private ProblemTreeViewer createViewer(Composite composite) {
		return  new PackageExplorerProblemTreeViewer(composite, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
	}
	/**
	 * Answers whether this part shows the packages flat or hierarchical.
	 * 
	 * @since 2.1
	 */
	public boolean isFlatLayout() {
		return fIsCurrentLayoutFlat;
	}
	
	private void setProviders() {
		
		fContentProvider= createContentProvider();
		fContentProvider.setIsFlatLayout(fIsCurrentLayoutFlat);
		fViewer.setComparer(createElementComparer());
		fViewer.setContentProvider(fContentProvider);
	
		fLabelProvider= createLabelProvider();
		fLabelProvider.setIsFlatLayout(fIsCurrentLayoutFlat);
		fViewer.setLabelProvider(new DecoratingJavaLabelProvider(fLabelProvider, false));
		
	}
	
	void toggleLayout() {