bug#33532: 26.1; set-window-configuration does not restore display start

[martin rudalics <rudalics@gmx.at>]

 > Then maybe instead of immediately modifying values in windows (like
 > e.g. comint-postoutput-scroll-to-bottom uses get-buffer-window-list
 > and comint-adjust-window-point) and instead of trying to do the same
 > in window configurations/states, better would be to modify these values
 > when windows are restored from window configurations/states/prev-next-buffers?

That was my idea when I proposed to go to the buffer's point when
restoring a configuration/state and the buffer had been reverted since
the configuration was saved.  Note that a configuration already has to
display some live buffer when the one it stored got killed since it was
saved.  Still, it might not be what users want, especially if they use
configurations to show the same buffer in multiple windows.

Note in this context that the collector does not scan window
configurations specially (or at least I cannot see where it does that
or whether any pointers in a configuration are weak).  So if you save
many configurations (or states) and kill buffers often, the dead
buffer objects and the markers these configurations save - including
those from the windows' previous and next buffers - will steadily pile
up.  If someone knows better, please correct me.

martin