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
receivedKeyDown = false;
										try {
											Thread.sleep(autoActivationDelay);
										} catch (InterruptedException e) {
										}
										if (!isValid() || receivedKeyDown) {
											return;
										}
										getControl().getDisplay().syncExec(
												new Runnable() {
													public void run() {
														openProposalPopup(true);
													}
												});
									}
								};
								Thread t = new Thread(runnable);
								t.start();
							} else {
								
								
								
								
								getControl().getDisplay().asyncExec(
										new Runnable() {
											public void run() {
												if (isValid()) {
													openProposalPopup(true);
												}
											}