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
case SWT.END:
						newSelection = proposalTable.getItemCount() - 1;
						if (e.type == SWT.KeyDown) {
							
							e.doit = false;		
						}
						break;
						
					 
				    
				    
				    
					case SWT.ARROW_LEFT:
					case SWT.ARROW_RIGHT:
						if (e.type == SWT.Traverse) {
							e.doit = false;
						} else {
							e.doit = true;
							String contents = getControlContentAdapter().getControlContents(
									getControl());
							 
							
							
							if (contents.length() > 0) {
								asyncRecomputeProposals(filterText);
							}
						}
						break;