bug#71774: 31.0.50; Hash table weakness broken?

[martin rudalics]

> Thanks for the report, but I wouldn't read too much into that. There
> could always be a stray reference to an object that is otherwise
> expected to be dead. Sometimes because of the conservative roots,
> sometimes from internal state we don't think about.

I tried once more with some 10 runs of automatic garbage collection
triggered in between and the result is the same.  Neither ambiguous
roots nor internal state can explain that new behavior IMHO.

> There is never a guarantee that any particular object is treated as
> dead by the GC. It's more of a general ambition.

A dead object that survives several collection cycles qualifies as a
leak in my view.

> As far as I can tell, it works as expected. Sometimes there is a
> stubborn value that just doesn't seem to want to be collected, but
> it's probably just a stray value on the stack, or a hidden reference
> that got stashed somewhere by the REPL.

This does not explain the change in behavior from all versions from
Emacs 24 up to and including Emacs 29 here to the current behavior.  A
version of Emacs 30 from early October 2023 still works correctly here.
A version from November 9th exhibits the new behavior.  I can try to
bisect from there but this takes much time on my slow machines.

martin