Bug 43488 [typing] BadPositionCategoryException in LinkedPositionManager
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/link/contentassist/ContentAssistant2.java
* 
	 * @return <code>true</code> if in auto insertion mode
	 * @since 2.0
	 */
	boolean isAutoInserting() {
		return fIsAutoInserting;
	}
	
	/**
	 * Installs and uninstall the listeners needed for autoactivation.
	 * @param start <code>true</code> if listeners must be installed,
	 * 	<code>false</code> if they must be removed
	 * @since 2.0
	 */
	private void manageAutoActivation(boolean start) {			
		if (start) {
			
			if (fViewer != null && fAutoAssistListener == null) {
				fAutoAssistListener= new AutoAssistListener();
				if (fViewer instanceof ITextViewerExtension) {
					ITextViewerExtension extension= (ITextViewerExtension) fViewer;
					extension.appendVerifyKeyListener(fAutoAssistListener);
				} else {
					StyledText textWidget= fViewer.getTextWidget();
					if (Helper2.okToUse(textWidget))
						textWidget.addVerifyKeyListener(fAutoAssistListener);
				}
			}
			
		} else if (fAutoAssistListener != null) {