bug#74224: [PATCH][scratch/igc] pgtk: fix crashing bug in atimer used for checking scaling

["Gerd Möllmann" <gerd.moellmann@gmail.com>]

Fejfighter <fejfighter@gmail.com> writes:

> This patch marks 2 outstanding ambiguous roots and appears to solve
> crashing bugs I had been experiencing with igc/mps and pgtk.
>
> I have run this locally today, and I would have normally faced crashes
> at timer expiration, this appears to be holding up.

Thanks for the report, Jeff! Nice to see that someone besides me is
using this :-).

I think I see why the change in atimer.c is necessary: pgtk stores a
struct frame * as client_data in an atimer structure. That's a Lisp
object that can move during GC. Understood.

The other change in pgtkterm.c I don't understand. AFAICS, x_id_name of
the display_info structure is indeed only used as a character buffer
into which characters from Lisp strings are memcpy'd. Could you please
explain that one? (I'm macOS only, so I don't know anything about pgtk,
if that matters.)