Re: Slur_proto_engraver segfault

[David Kastrup]

Dan Eble <address@hidden> writes:

> Forgive me for being brief, but I thought I should at least mention
> this in case someone would like to approach it with code review:
>
> Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
> 0 lilypond 0x001f35ff Slur_proto_engraver::derived_mark() const + 79
> 1 lilypond 0x00279696 Translator::mark_smob() const + 54
> 2 libguile.17.dylib 0x00718aaa scm_gc_mark_dependencies + 1050

Without further information, it's not really possible to figure out
what's wrong here.  The crash is while in garbage protection, ostensibly
trying to mark already freed structures.  It's not really clear how
those would be coming about since they should have been marked at the
previous garbage collection and/or protected in between.

So it's plausible that the error would be somewhere else, but indeed
Slur_proto_engraver has seen definite changes in the last release.

So an actual input file triggering the problem would be important.
Preferably, of course, when the error would be reproducible.

Also a disassembly of Slur_proto_engraver::derived_mark() so that one
has a chance to figure out the exact instruction of the crash.

-- 
David Kastrup