bug#34038: 26.1; set-window-start sometimes fails to set window start

[martin rudalics]

> This indeed seems to be a critical factor: an empty last line that
> appears as the first line of the window.

I think I now distilled a fairly simply recipe to watch the problem.
Load the attached file with emacs -Q and type C-.

Note that *scratch* contains no empty line when finally displayed.
Also, here C-. displays the desired result with window-start at
point-max for a short moment before making the buffer fully visible.
Setting 'scroll-conservatively' to 101 fixes the problem.

martin

foobar.el
Description: application/emacs-lisp