Bug 66923 [typing]Can delete word (Ctrl-Backspace) on read only file
When you open read-only java file, all editing functions are disabled except deleting with Ctrl-Backspace and Ctrl-Del, then it is imposible to save this file. On simple text file it works ok - it blocks all edditing functions (including Ctrl-Backspace). I am using build 200406111814
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
if (PreferenceConstants.EDITOR_FOLDING_PROVIDER.equals(property)) {
				if (sourceViewer instanceof ProjectionViewer) {
					ProjectionViewer projectionViewer= (ProjectionViewer) sourceViewer;
					if (fProjectionModelUpdater != null)
						fProjectionModelUpdater.uninstall();
					
					fProjectionModelUpdater= JavaPlugin.getDefault().getFoldingStructureProviderRegistry().getCurrentFoldingProvider();
					if (fProjectionModelUpdater != null) {
						fProjectionModelUpdater.install(this, projectionViewer);
					}
				}
				return;
			}
			
		} finally {
			super.handlePreferenceStoreChanged(event);
		}
	}
	
	/**
	 * Initializes the given viewer's colors.
	 * 
	 * @param viewer the viewer to be initialized
	 * @since 3.0
	 */
	protected void initializeViewerColors(ISourceViewer viewer) {
		
	}
	private boolean isJavaEditorHoverProperty(String property) {