Hi Kevin,

Kevin Ryde <user42@zip.com.au> writes:

> "Marco Maggi" <marco.maggi-ipsu@poste.it> writes:
>>
>> guile> (equal? (values 1 2) (values 1 2))
>> ERROR: Stack overflow
>
> Thanks, looks like a bug introduced by recursing into structs in
> equal?.  I guess scm_i_struct_equalp should check and ignore a field
> type "s" ...

Indeed, good guess!

I propose the following simple fix.  Ok to apply?

Actually, `scm_i_struct_equalp ()' should also compare the "tail
elements" (when there are tail elements), but their semantics are a
little fuzzy to me.  In particular, I don't understand why the size of
the tail array can be specified in both `make-vtable-vtable' and
`make-struct': What does that mean?  Which one should really be taken
into account?  It seems that the code is a bit unclear on this too:

  guile> (define v (make-vtable-vtable "pr" 0))
  guile> (define s (make-struct v 123))
  guile> (struct-ref s 10)
  Segmentation fault

(Looks like the API is so complex that few people actually bothered to
use it to its full extents.  ;-))

Thanks,
Ludovic.