bug#59963: 29.0.50; 'window-max-chars-per-line' doesn't always work on GUI without fringe

[martin rudalics <rudalics@gmx.at>]

 > Using left/right-fringe-width in window-max-chars-per-line is IMO
 > wrong, we should use window-fringes (which will return correct values
 > both when the window has its private valuesm, either via
 > set-window-fringes or via assignment of left/right-fringe-width, and
 > when it doesn't).

This should have been done at the time that function was installed.  If
you do it now, you may break valid code like

(let (max-chars)
   (setq right-fringe-width 0)
   (setq max-chars (window-max-chars-per-line))
   (set-window-buffer nil (window-buffer))
   max-chars)

which currently yields 79 and would yield 80 with your proposal.

martin