Dear Maintainer,

Follow these steps to reproduce the bug.

1. Remove all widgets, except Icons-Only Task Manager, from the default panel.
2. Configure the panel with the following settings.
    a. Position: Bottom
    b. Alignment: Center
    c. Width: Fit content
    d. Visibility: Dodge windows
    e. Opacity: Adaptive
    f. Style: Floating
3. Make sure that none of the currently open applications are causing
   the panel to hide.
4. Start an application that doesn't open maximized and is not pinned to
   the task manager. KCalc is a good choice.
4. Close the application opened in the previous step and do not perform
   any other action.

Notice that a blank spot remains in the panel and the panel does shrink
to fit the remaining icons in the task manager.

When the panel is configured to fit its content, it must shrink
automatically when the last application is closed.