Re: Issue 818 in lilypond: Bus error when adding Instrument_name_engraver to StaffGroup and outputting MIDI.

[Neil Puttock]

On 2 September 2010 09:20, Phil Holmes <address@hidden> wrote:

> I've had this sort of behaviour in the dim-and-distant with a compiler bug
> on VMS.  I was using 2 pointers pointing to the same memory location, and
> changing the value with pointer 1 then reading it with pointer 2.  The
> optmiser didn't spot that and assumed the second value was unchanged.
> Clearly, if the value pointed to had been a pointer itself, it could have
> been uninitialised.  Bu**er to spot, since under debug it was fine.
>
> I'm betting there's an uninitialised pointer somewhere in there, but most of
> the time (by luck) it doesn't point to an invalid location.  But with some
> compiler settings, on some OSes, it does.

It's really bizarre.  All the code I've looked over seems fine.  I've
tried using valgrind, but it hasn't picked up any significant changes
between working and broken versions.

I have a patch which fixes it, but I can't explain why it works.

Cheers,
Neil