Bug 147377 [Field Assist] - open proposal popup should close when there are no valid proposals left
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
if (USE_VIRTUAL) {
				proposalTable = new Table(parent, SWT.H_SCROLL | SWT.V_SCROLL
						| SWT.VIRTUAL);
				Listener listener = new Listener() {
					public void handleEvent(Event event) {
						handleSetData(event);
					}
				};
				proposalTable.addListener(SWT.SetData, listener);
			} else {
				proposalTable = new Table(parent, SWT.H_SCROLL | SWT.V_SCROLL);
			}
			
			recomputeProposals(filterText);
			proposalTable.setHeaderVisible(false);
			proposalTable.addSelectionListener(new SelectionListener() {
				public void widgetSelected(SelectionEvent e) {
					
					
					if (e.item == null) {
						if (infoPopup != null) {
							infoPopup.close();
						}
					} else {
						TableItem item = (TableItem) e.item;
						IContentProposal proposal = (IContentProposal) item
								.getData();
						showProposalDescription(proposal.getDescription());
					}
				}