bug#20832: 25.0.50; todo-show accidentally deleted my todo file.

[martin rudalics]

> This is bad :'( It seems one should not change the buffer in a minibuffer
> window. Perhaps it would be good if this was documented in
> the docstring of set-window-buffer.

You should use ‘set-window-buffer’ in application programs only if you
know what you're doing.  From the Elisp manual:

     When writing an application, you should normally use the
     higher-level functions described in *Note Switching Buffers::,
     instead of calling `set-window-buffer' directly.

While the minibuffer window is selected, ‘minibuffer-selected-window’
can be used to get the previously selected window.

martin