Crash while moving plugins between different panels
xfce4-panel version: 4.17.0git-6b0fe437 (Xfce 4.16)
When attempting to move plugins between 2 or more different panels, the plugin is removed from the originating panel but does not arrive at the destination panel. Moving the plugin into a different position on the same panel still works.
The following is displayed in .xsession-errors when this happens.
(xfce4-panel:110067): Gtk-CRITICAL **: 16:01:43.355: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed
(xfce4-panel:110067): GLib-GObject-WARNING **: 16:01:47.019: instance with invalid (NULL) class pointer
(xfce4-panel:110067): GLib-GObject-CRITICAL **: 16:01:47.020: g_signal_emit_valist: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
(xfce4-panel:110067): GLib-GObject-CRITICAL **: 16:01:47.020: g_object_set_qdata: assertion 'G_IS_OBJECT (object)' failed
(xfce4-panel:110067): GLib-GObject-WARNING **: 16:01:47.020: instance with invalid (NULL) class pointer
(xfce4-panel:110067): GLib-GObject-CRITICAL **: 16:01:47.020: g_signal_handlers_destroy: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
(xfce4-panel:110067): GLib-GObject-WARNING **: 16:01:47.020: instance with invalid (NULL) class pointer
(xfce4-panel:110067): GLib-GObject-CRITICAL **: 16:01:47.020: g_signal_handlers_destroy: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
(xfce4-panel:110067): GLib-GObject-CRITICAL **: 16:01:47.020: g_object_unref: assertion 'old_ref > 0' failed