In the tag browser, ensure that "Change category icon" appears only on top-level nodes. This avoids confusion about what which items are affected in hierarchical categories.

src/calibre/gui2/tag_browser/view.py

@@ -650,6 +650,7 @@ class TagsView(QTreeView):  # {{{
                         partial(self.context_menu_handler, action='manage_searches',
                                 category=tag.name if tag else None))
 
+                if tag is None:
                     self.context_menu.addSeparator()
                     self.context_menu.addAction(_('Change category icon'),
                             partial(self.context_menu_handler, action='set_icon', key=key))