bug#41321: 27.0.91; Emacs aborts due to invalid pseudovector objects

[Pip Cet]

On Sat, May 23, 2020 at 10:38 PM Stefan Monnier
<monnier@iro.umontreal.ca> wrote:
> >> If I'm reading this correctly, it's of some concern for wide-int
> >> builds: the two 32-bit halves of a Lisp_Object are stored
> >> non-consecutively.
>
> This shouldn't be a problem: wide-int builds use MSB tagging, so all
> Lisp_Objects which contain a pointer have their lowest 32bits exactly
> identical to that pointer (and the higher 32bits just contain the tag).

As I said, I don't believe that's true for symbols. Qnil is always
binary 0, so we offset all symbols by the offset of lispsym.

> So we'll find them in the stack even if the two halves are separate
> simply because the pointer-part will be found like any other pointer.

Yes, that's what I meant to say when I said it should still work for
pseudovectors.