bug#18233: 24.3.92; Use of (frame-selected-window) in mode-line-format

[Christopher Schmidt]

severity: wishlist

    emacs -q
    C-x 2
    M-: (push '(:eval (if (eq (frame-selected-window)
                              (selected-window))
                          "A" "B"))
              mode-line-format) RET

Both mode-lines expose an 'A'-Marker.

In Emacs 24.3 the mode-line of the window that is not the user selected
one is marked with 'B'.

I realise this subtle change is not exactly a bug.  The old behaviour is
useful and used already, though.[1]

[1] 
https://github.com/milkypostman/highline/blob/1621662e886afa5948e8fccf0037d6c2a718e9a0/highline.el#L326