Bug 62401 [Actions] ReferenceCleanerThread in ActionContributionItem cause application can not exit normally.
When the standalone application exit, the display disposed, will call ReferenceCleanerThread.stopCleaning() method, it simply set the running field to false, but "reference = referenceQueue.remove();" in line 196 still blocking. And you must call System.exit() explicitlly to terminate the currently running Java Virtual Machine. so I think it is a bug. My env: XP home edition, jdk 1.4.2_04, and eclipse-SDK-I20040514-win32 Regards, Eric
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ActionContributionItem.java
((ToolItem) widget).setDisabledImage(disabledImage);
				}
				((ToolItem) widget).setHotImage(hoverImage);
				((ToolItem) widget).setImage(image);
				return image != null;
			}
		} else if (widget instanceof Item || widget instanceof Button) {
			
			Image image = cache.getImage(action.getHoverImageDescriptor());
			if (image == null) {
				image = cache.getImage(action.getImageDescriptor());
			}
			
			if (image == null && forceImage) {
				image = cache.getMissingImage();
			}
			if (widget instanceof Item) {
				((Item) widget).setImage(image);
			} else if (widget instanceof Button) {
				((Button) widget).setImage(image);
			}
			return image != null;
		}
		return false;
	}
	/**
	 * Shorten the given text <code>t</code> so that its length doesn't