Bug 132798 [Field Assist] - Pressing Backspace at offset 0 should not reload field assist popup
N20060322-0010. After migrating the Find/Replace dialog to the new field assist support I found the following blooper: pressing the Backspace key at offset 0 reloads the field assist popup. Test Case: 1. in a text editor press Ctrl+F 2. enable regex search 3. in the Find filed press Ctrl+Space 4. continuously press Backspace ==> each time the proposal list is reloaded.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
if (proposal == null || labelProvider == null) {
				return null;
			}
			return labelProvider.getImage(proposal);
		}
		/*
		 * Return an empty array. Used so that something always shows in the
		 * proposal popup, even if no proposal provider was specified.
		 */
		private IContentProposal[] getEmptyProposalArray() {
			return new IContentProposal[0];
		}
		/*
		 * Answer true if the popup is valid, which means the table has been
		 * created and not disposed.
		 */
		private boolean isValid() {
			return proposalTable != null && !proposalTable.isDisposed();
		}
		/*
		 * Return whether the receiver has focus.
		 */
		private boolean hasFocus() {
			if (!isValid()) {
				return false;
			}
			return getShell().isFocusControl()
					|| proposalTable.isFocusControl();
		}
		/*