Re: [Emacs-diffs] master 29d1c72: Introduce new value t for compilation-context-lines to eliminate scrolling

[Eli Zaretskii]

> Date: Sun, 25 Aug 2019 19:06:37 +0000
> From: Alan Mackenzie <address@hidden>
> Cc: address@hidden
> 
> > 2- Why insert a prefix string (an "inserted arrow") instead of using
> >    a "regular overwriting arrow"?
> 
> Because the overwriting arrow would obliterate the first two characters
> of the file name.  I actually tried this first, and it wasn't
> satisfactory.  This contrasts with another use of the overwriting arrow
> in edebug, where (usually) only WS gets overwritten, and it is important
> not to disturb the visible indentation.

Did you consider to use the display margin instead?  You can have an
overlay display in the margin by putting a 'display' property on the
overlay string.  The advantage of using the margin is that it will
keep the buffer text aligned.