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 (Character.isDefined(key)) {
						if (filterStyle == FILTER_CUMULATIVE) {
							filterText = filterText + String.valueOf(key);
						} else if (filterStyle == FILTER_CHARACTER) {
							filterText = String.valueOf(key);
						}
						
						asyncRecomputeProposals(filterText);
					}
					break;
				}
			}
		}
		/*
		 * Internal class used to implement the secondary popup.
		 */
		private class InfoPopupDialog extends PopupDialog {
			/*
			 * The text control that displays the text.
			 */
			private Text text;
			/*
			 * The String shown in the popup.
			 */
			private String contents = EMPTY;
			/*
			 * Construct an info-popup with the specified parent.
			 */
			InfoPopupDialog(Shell parent) {
				super(parent, PopupDialog.HOVER_SHELLSTYLE, false, false,