Bug 16181 Tab key doesn't work in editor when 'Insert spaces for tabs' enabled
Using integration build 0515, pressing Tab in an editor window doesn't do anything when 'Insert spaces for tabs' is selected. The editor is marked as unsaved, but no spaces appear.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
* Changed behavior to make sure that if called inside a regular save (because
	 * of deletion of input element) there is a way to report back to the caller.
	 */	
	protected void performSaveAs(IProgressMonitor progressMonitor) {
		
		Shell shell= getSite().getShell();
		
		SaveAsDialog dialog= new SaveAsDialog(shell);
		IEditorInput input = getEditorInput();
		
		IFile original= null;
		if (input instanceof IFileEditorInput)
			original= ((IFileEditorInput) input).getFile();
			
		if (original != null)
			dialog.setOriginalFile(original);
			
		if (dialog.open() == Dialog.CANCEL) {
			if (progressMonitor != null)
				progressMonitor.setCanceled(true);
			return;
		}
			
		IPath filePath= dialog.getResult();
		if (filePath == null) {
			if (progressMonitor != null)
				progressMonitor.setCanceled(true);
			return;
		}