Re: Nasty GC bug

[Paul Eggert]

On 08/24/2012 12:26 AM, Dmitry Antipov wrote:
> Suggested fix is to use MEM_TYPE_NON_LISP for spare memory, e.g.:

Thanks for finding this bug.

That patch doesn't look quite right if ! USE_LSB_TAG, since
in that case lisp_align_malloc won't correctly report a
failure in the section of code that checks whether the
memory just allocated can be addressed through a Lisp
object's pointer.  Also, what about dont_register_blocks
and allocated_mem_type?

Instead, how about marking the spare conses with Vdead
and the spare strings with NULL data?  Admittedly I
haven't had time to think this through....