Bug 96917 [implementation] If two editors use the 2.x-compatible API, one or both doesn't work
At least one problem is that 3.0 installs partitioners for every editor that might possibly edit a file, but each editor expects its own partitioner to be installed. Leading to the famous white screen with blue line.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/ClassFileDocumentProvider.java
public _FileSynchronizer(IFileEditorInput fileEditorInput) {
			super(fileEditorInput);
		}
	}
	/**
	 * Bundle of all required informations.
	 */
	protected class ClassFileInfo extends FileInfo {
		ClassFileSynchronizer fClassFileSynchronizer= null;
		ClassFileInfo(IDocument document, IAnnotationModel model, _FileSynchronizer fileSynchronizer) {
			super(document, model, fileSynchronizer);
		}
		ClassFileInfo(IDocument document, IAnnotationModel model, ClassFileSynchronizer classFileSynchronizer) {
			super(document, model, null);
			fClassFileSynchronizer= classFileSynchronizer;
		}
	}
	
	private List fInputListeners= new ArrayList();
	/**