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
* 
	 * @return the location of this popup
	 */
	private Point getLocation() {
		StyledText text= fViewer.getTextWidget();
		Point selection= text.getSelection();
		Point p= text.getLocationAtOffset(selection.x);
		
		p.x -= fProposalShell.getBorderWidth();
		if (p.x < 0) p.x= 0;
		if (p.y < 0) p.y= 0;
		p= new Point(p.x, p.y + text.getLineHeight());
		p= text.toDisplay(p);
		if (p.x < 0) p.x= 0;
		if (p.y < 0) p.y= 0;
		return p;
	}
	/**
	 *Displays this popup and install the additional info controller, so that additional info
	 * is displayed when a proposal is selected and additional info is available.
	 */
	private void displayProposals() {
		if (fContentAssistant.addContentAssistListener(this, ContentAssistant2.PROPOSAL_SELECTOR)) {
			
			if (fDocumentListener == null)
				fDocumentListener=  new IDocumentListener()  {
					public void documentAboutToBeChanged(DocumentEvent event) {
						if (!fInserting)
							fDocumentEvents.add(event);
					}