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
int targetOffset= (JavaPairMatcher.RIGHT == anchor) ? offset + 1: offset + length;
		
		boolean visible= false;
		if (sourceViewer instanceof ITextViewerExtension3) {
			ITextViewerExtension3 extension= (ITextViewerExtension3) sourceViewer;
			visible= (extension.modelOffset2WidgetOffset(targetOffset) > -1);
		} else {
			IRegion visibleRegion= sourceViewer.getVisibleRegion();
			
			visible= (targetOffset >= visibleRegion.getOffset() && targetOffset <= visibleRegion.getOffset() + visibleRegion.getLength());
		}
		
		if (!visible) {
			setStatusLineErrorMessage(JavaEditorMessages.getString("GotoMatchingBracket.error.bracketOutsideSelectedElement"));			
			sourceViewer.getTextWidget().getDisplay().beep();
			return;
		}
		
		if (selection.getLength() < 0)
			targetOffset -= selection.getLength();
			
		sourceViewer.setSelectedRange(targetOffset, selection.getLength());
		sourceViewer.revealRange(targetOffset, selection.getLength());
	}
	/**
	 * Sets the given message as error message to this editor's status line.
	 * 
	 * @param msg message to be set
	 */
	protected void setStatusLineErrorMessage(String msg) {