Bug 90528 Editor icon does not show problem decoration for second instance
3.1 M6 - open a .java file that has errors or warnings - the editor tab icon has the problem decoration - Window > New Window - open the same file in the new window - the editor tab icon is missing the problem decoration
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
if (file != null)
				newExtension= file.getFileExtension();
		}
		
		return oldExtension.equals(newExtension);
	}
	/*
	 * @see org.eclipse.ui.texteditor.AbstractDecoratedTextEditor#isPrefQuickDiffAlwaysOn()
	 */
	protected boolean isPrefQuickDiffAlwaysOn() {
		
		
		IPreferenceStore store= getPreferenceStore();
		return store.getBoolean(AbstractDecoratedTextEditorPreferenceConstants.QUICK_DIFF_ALWAYS_ON);
	}
	
	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.JavaEditor#getAdapter(java.lang.Class)
	 */
	public Object getAdapter(Class required) {
		if (SmartBackspaceManager.class.equals(required)) {
			if (getSourceViewer() instanceof JavaSourceViewer) {
				return ((JavaSourceViewer) getSourceViewer()).getBackspaceManager();
			}
		}
		return super.getAdapter(required);
	}
	/**
	 * Returns the mutex for the reconciler. See https://bugs.eclipse.org/bugs/show_bug.cgi?id=63898
	 * for a description of the problem.