Comment 9 for bug 1151621

I've added GTK+ 3.0 as being affected, as this is actually a bug in GTK+ itself, it seems. Or at least, if it's not in GTK+, then it's either pygobject or libgirepository not correctly binding the methods.

It seems that software-center is making a valid call to get_selection_bounds() on a GtkSearchEntry widget, which implements the GtkEditable interface, and provides a get_selection-bounds() method. However, for some reason, this is being seen as an unbound method when called here, and the gtk_text_buffer_get_selection_bounds() method is being called instead, incorrectly, causing the TypeError.

I will implement a workaround in software-center so that the TypeError gets ignored (as the code in software-center is correct here), which may cause the Cut and Copy menu items to no longer work for the search entry. However, the standard key bindings, and the right-click context menu on the entry, will still work to copy/cut the selected text. Also, the Cut menu item will be removed as it's not used elsewhere, while Copy is used for copying text from other parts of the UI.