From: why the lucky stiff <ruby-core@...>
Date: 2004-05-24T01:07:28+09:00
Subject: Re: Syck CVS (was Re: [bug] [yaml] YAML.load([1,2,3].to_yaml.to_yaml))

ts wrote:

> 
>  If blockType == BLOCK_FOLD and qidx == 0 (which is this special case) it
>  will make (in QUOTECAT)
> 
>    qstr[-1] = '\n';
> 
>  This can corrupt the memory pool (qstr is malloced) and this is why it
>  crash when free() is called
>

Very good.  Thankyou, Guy.

> 
>  Now, syck can emit this
> 
> svg% ruby -ryaml -e 'puts "---\n...\n".to_yaml'
> --- >
> ---
> 
> ...
> 
> svg% 
> 
>  This is valid in YAML for a String object ?
>

Since "..." is the pause operator, this YAML should be indented.

  --- >
    ---

    ...


>  Finally, for the other bug [ruby-talk:100706]
> 
> #14 0x0806a996 in rb_gc () at gc.c:1328
> #15 0x08069861 in rb_newobj () at gc.c:386
> #16 0x0806b8a2 in hash_alloc (klass=0) at hash.c:183
> #17 0x0806b901 in rb_hash_new () at hash.c:195
> #18 0x400b4921 in syck_parser_new (argc=0, argv=0x0, class=1074314424)
>     at rubyext.c:772
> 
>  The GC is called when syck_parser_new() is not finished
> 
>  in syck_new_parser(), root is not set to zero.
> 
>  When the GC will find pobj on the stack, it will call syck_mark_parser()
>  which call rb_gc_mark(parser->root);
> 
>  At this step, you can't predict what ruby will do :
>    * segfault,
>    * unknown object
>    * infinite loop
>    * ...
> 

It's okay to set parser->root to zero, then?  When rb_gc_mark gets
called and parser->root is 0 (Qnil), it will ignore that node, right?
Or do I use rb_gc_mark_maybe?

_why