Bug 46394 RCP: Add marker action disabled for Java editor
N20031111 Start fresh workspace and create a class in a Java project. The following actions are disabled: Edit > Add Bookmark... Edit > Add Task... It works in the standard text editor.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
while (i.hasNext()) {
			AnnotationPreference annotationPref= (AnnotationPreference) i.next();
			if (annotationPref.getAnnotationType().equals(type)) {
				String key= annotationPref.getIsGoToNextNavigationTargetKey();
				if (key != null && preferences.getBoolean(key))
					return true;
			}
		}
		return false;
	}
	/**
	 * Computes and returns the source reference that includes the caret and
	 * serves as provider for the outline page selection and the editor range
	 * indication.
	 * 
	 * @return the computed source reference
	 * @since 3.0
	 */
	protected ISourceReference computeHighlightRangeSourceReference() {
		ISourceViewer sourceViewer= getSourceViewer();
		if (sourceViewer == null)
			return null;
			
		StyledText styledText= sourceViewer.getTextWidget();
		if (styledText == null)
			return null;
		
		int caret= 0;
		if (sourceViewer instanceof ITextViewerExtension3) {
			ITextViewerExtension3 extension= (ITextViewerExtension3)sourceViewer;