bug#52929: 27.1; Images are sometimes not fully displayed

[Eli Zaretskii]

> From: martin rudalics <rudalics@gmx.at>
> Date: Sat, 1 Jan 2022 17:01:27 +0100
> Cc: 52929@debbugs.gnu.org
> 
> When a window has no right fringe, Emacs by default usurps the rightmost
> character on each text line so it can indicate there whether that line
> is truncated or continued.  The maximum width of the special glyph to be
> displayed there (typically a "$" or a "\") is subtracted from the
> maximum width of the display area of that window.  So with the right
> fringe turned off, you as a rule always lose one column to the display
> engine even when displayed lines are never truncated or continued.
> 
> But Eli can explain it better.

I think you explained it very clearly, I have nothing to add, except
the obvious: the no-special-glyphs frame parameter, if its value is
non-nil, suppresses the display of the truncation and continuation
glyphs, and thus the column that the display engine needs for that is
free for other needs.