Index: lib/alexandria/ui/callbacks.rb
===================================================================
--- lib/alexandria/ui/callbacks.rb	(revision 1067)
+++ lib/alexandria/ui/callbacks.rb	(revision 1072)
@@ -19,6 +19,9 @@
 module Alexandria
   module UI
     module Callbacks
+
+      include Logging
+
       def on_new widget, event
         name = Library.generate_new_name(@libraries.all_libraries)
         library = Library.load(name)
@@ -208,6 +211,12 @@
       def on_delete widget, event
         library = selected_library
         books = @library_listview.focus? ? nil : selected_books
+        is_smart = library.is_a?(SmartLibrary)
+        last_library = (@libraries.all_regular_libraries.length == 1)
+        if (!is_smart && last_library)
+          log.warn { "Attempted to delete last library, fix GUI" }
+          return
+        end
         if library.empty? or ReallyDeleteDialog.new(@main_app,
                                                     library,
                                                     books).ok?
Index: lib/alexandria/ui/ui_manager.rb
===================================================================
--- lib/alexandria/ui/ui_manager.rb	(revision 1067)
+++ lib/alexandria/ui/ui_manager.rb	(revision 1072)
@@ -306,6 +306,7 @@
 
         if event_is_right_click event
           log.debug { "library right click!" }
+          library_already_selected = true
           if path = widget.get_path_at_pos(event.x, event.y)
             obj, path = widget.is_a?(Gtk::TreeView) \
               ? [widget.selection, path.first] : [widget, path]
@@ -313,6 +314,7 @@
 
             unless obj.path_is_selected?(path)
               log.debug { "Select #{path}" }
+              library_already_selected = false
               widget.unselect_all
               obj.select_path(path)
             end
@@ -321,10 +323,25 @@
           end
 
           menu = determine_library_popup widget, event
-          Gtk.idle_add do
-            menu.popup(nil, nil, event.button, event.time)
-            false
+
+          # Fixes part of bug #25021.
+          #
+          # If the library was not selected when it was right-clicked
+          # we should select the library first (we call on_focus
+          # manually, since the above call to obj.select_path(path) doesn't
+          # seem to suffice).
+          #
+          # Then we wait a while and only *then* pop up the menu.
+
+          
+          if library_already_selected
+            sensitize_library selected_library
+            Gtk.idle_add do
+              menu.popup(nil, nil, event.button, event.time)
+              false
+            end
           end
+          
         end
       end
 
@@ -972,7 +989,8 @@
         @actiongroup["AddBook"].sensitive = !smart
         @actiongroup["AddBookManual"].sensitive = !smart
         @actiongroup["Properties"].sensitive = true
-        @actiongroup["Delete"].sensitive = true #(@libraries.all_regular_libraries.length > 1)
+        can_delete = smart || (@libraries.all_regular_libraries.length > 1)
+        @actiongroup["Delete"].sensitive = can_delete ## true #(@libraries.all_regular_libraries.length > 1)
         log.debug { "sensitize_library delete: #{@actiongroup["Delete"].sensitive?}" }
       end