Bug 139063 [Field Assist] - API - behavior of text insert not taking selection into account
Field Assist Example - set acceptance style to "Insert into field content" - type some text into the text and combo - select a subset of the text and invoke content assist - choose a proposal in the popup outcome: text is inserted at the insertion point expected: text should be inserted, but should replace any selected text Is this a regression?
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
* Open the proposal popup and display the proposals provided by the
	 * proposal provider. This method returns immediately. That is, it does not
	 * wait for a proposal to be selected. This method is used by subclasses to
	 * explicitly invoke the opening of the popup. If there are no proposals to
	 * show, the popup will not open and a beep will be sounded.
	 */
	protected void openProposalPopup() {
		openProposalPopup(false);
	}
	/**
	 * Close the proposal popup without accepting a proposal. This method
	 * returns immediately, and has no effect if the proposal popup was not
	 * open. This method is used by subclasses to explicitly close the popup
	 * based on additional logic.
	 * 
	 * @since 3.3
	 */
	protected void closeProposalPopup() {
		if (popup != null) {
			popup.close();
		}
	}
	/*
	 * A content proposal has been accepted. Update the control contents
	 * accordingly and notify any listeners.
	 * 
	 * @param proposal the accepted proposal
	 */
	private void proposalAccepted(IContentProposal proposal) {
		switch (proposalAcceptanceStyle) {