Re: Naming _another_ lacking puzzle piece

[Trevor Daniels]

David Kastrup wrote Saturday, October 13, 2012 1:01 AM
> 
> In ly/music-functions-init.ly I see code like the following:
> 
> crossStaff =
> #(define-music-function (parser location notes) (ly:music?)
>  (_i "Create cross-staff stems")
>  #{
>  \override Stem #'cross-staff = #cross-staff-connect
>  \override Flag #'style = #'no-flag
>  $notes
>  \revert Stem #'cross-staff
>  \revert Flag #'style
> #})
> 
> There is a problem with that: in terms of stack operations, \override
> and \revert are not opposing pairs: \override is pop+push (so that
> multiple overrides in a row don't accrue cruft), \revert is pop.  So the
> net effect of this sequence is "pop", while it should be neutral.

What would be the effect of this?  The implication is that something
goes wrong, but bugs in this area have never been reported, AFAIK.

I understand stacks, pop and push, but I'm clearly missing something 
here.  Perhaps it's due to my unfamiliarity with the structure of the 
stack(s). 
 
Trevor