Bug 125011 [Contributions] ActionContributionItem should use text for tooltip in toolitems
If an action is added to a toolbar, and it has a name, but no tooltip set, the name should be used as the tooltip (except when the text is actually displayed on the toolitem using setText()) Clients sometimes forget to set the tooltip text when no specific tooltip message exists.
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ActionContributionItem.java
public final void update() {
        update(null);
    }
    /**
     * Synchronizes the UI with the given property.
     *
     * @param propertyName the name of the property, or <code>null</code> meaning all applicable
     *   properties 
     */
    public void update(String propertyName) {
        if (widget != null) {
            			
            boolean textChanged = propertyName == null
                    || propertyName.equals(IAction.TEXT);
            boolean imageChanged = propertyName == null
                    || propertyName.equals(IAction.IMAGE);
            boolean tooltipTextChanged = propertyName == null
                    || propertyName.equals(IAction.TOOL_TIP_TEXT);
            boolean enableStateChanged = propertyName == null
                    || propertyName.equals(IAction.ENABLED)
                    || propertyName
                            .equals(IContributionManagerOverrides.P_ENABLED);
            boolean checkChanged = (action.getStyle() == IAction.AS_CHECK_BOX || action
                    .getStyle() == IAction.AS_RADIO_BUTTON)
                    && (propertyName == null || propertyName
                            .equals(IAction.CHECKED));
            if (widget instanceof ToolItem) {
                ToolItem ti = (ToolItem) widget;
                String text = action.getText();