Bug 42587 Left over from content assist
M3 - set preference that content assist should overwrite - open content assist on some word so that the rest of the word is indicated to be overwritten - transfer focus to the content assist widget using TAB - Esc -> overwrite indication is still there
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/link/contentassist/CompletionProposalPopup2.java
private ICompletionProposal[] fFilteredProposals;
	
	private ICompletionProposal[] fComputedProposals;
	
	private int fInvocationOffset;
	
	private int fFilterOffset;
	
	private String fLineDelimiter;
	
	/**
	 * Creates a new completion proposal popup for the given elements.
	 * 
	 * @param contentAssistant the content assistant feeding this popup
	 * @param viewer the viewer on top of which this popup appears
	 * @param infoController the info control collaborating with this popup
	 * @since 2.0
	 */
	public CompletionProposalPopup2(ContentAssistant2 contentAssistant, ITextViewer viewer, AdditionalInfoController2 infoController) {
		fContentAssistant= contentAssistant;
		fViewer= viewer;
		fAdditionalInfoController= infoController;
	}
	/**
	 * Computes and presents completion proposals. The flag indicates whether this call has
	 * be made out of an auto activation context.
	 * 
	 * @param autoActivated <code>true</code> if auto activation context
	 * @return an error message or <code>null</code> in case of no error
	 */