Re: crash when \setting a grob if it is used afterwards

[Colin Hall]

On Thu, Dec 13, 2012 at 09:46:30AM +0100, David Kastrup wrote:
> Eluze <address@hidden> writes:
> 
> > David Kastrup wrote
> >> Eluze &lt;
> >
> >> eluzew@
> >
> >> &gt; writes:
> >> 
> >>> David Kastrup wrote
> >>>> For an explanation, see
> >>>> &lt;URL:http://code.google.com/p/lilypond/issues/detail?id=2870#c7&gt;
> >>>
> >>> well, here she only says:
> >>>
> >>> GNU LilyPond 2.17.8
> >>> Processing `test.ly'
> >>> Parsing...
> >>> Interpreting music...
> >> 
> >> You have to try using the broken internals afterwards. 
> >
> > where (and what) are these???
> 
> Well, I referred to comment #7 which gives
> \set Voice #'Accidental #'color #red
> as an example (obviously I forgot that set does not allow for
> subproperty setting).  One crashing example would be
> 
> 
> {
>   \set Voice.Accidental = #'(color red)
>   cis1
> }
> 
> >> At any rate, the
> >> explanation is applicable to your crashes.
> >
> > I guess so

>From reading this thread I understand that there are constraints on
the use of \set which Eluze's source failed to observe.

David's link to an issue comment explains why this is so.

The failure to adhere to the contraints resulted in Lilypond failing
silently or crashing, so Eluze would like to have been warned about
his/her faulty input.

The ability to set arbitrary properties is a widely used feature of
Lilypond.

One of the following applies:

a) Lilypond can be changed to include warnings for the user error
reported here, and I should create an enhancement tracker.

b) The flexibility that allows users to crash Lilypond by misusing set
is a key feature, we'd like to retain it, and the bug report should be
rejected.

Could one of the devs please advise which course of action I should take?

Cheers,
Colin.

-- 

Colin Hall