Bug 12116 [Contributions] widgets: MenuManager.setImageDescriptor() method needed
Currently there seems to be no API to assign image to menu item that contains submenu, the only way is to override MenuManager.fill() methods. That seems to be inconsistent.
bundles/org.eclipse.jface/src/org/eclipse/jface/action/MenuManager.java
for (Iterator e = clean.iterator(); e.hasNext();) {
                    IContributionItem src = (IContributionItem) e.next();
                    IContributionItem dest;
                    
                    if (srcIx < mi.length) {
						dest = (IContributionItem) mi[srcIx].getData();
					} else {
						dest = null;
					}
                    if (dest != null && src.equals(dest)) {
                        srcIx++;
                        destIx++;
                    } else if (dest != null && dest.isSeparator()
                            && src.isSeparator()) {
                        mi[srcIx].setData(src);
                        srcIx++;
                        destIx++;
                    } else {
                        int start = menu.getItemCount();
                        src.fill(menu, destIx);
                        int newItems = menu.getItemCount() - start;
                        for (int i = 0; i < newItems; i++) {
                            MenuItem item = menu.getItem(destIx++);
                            item.setData(src);
                        }
                    }