Re: NT Emacs crashes when selecting a menubar item

[David Ponce]

> Is this comment in w32menu.c inaccurate?
>
>      /* Now GC cannot happen during the lifetime of the widget_value,
>          so it's safe to store data from a Lisp_String, as long as
>          local copies are made when the actual menu is created.
>          Windows takes care of this for normal string items, but
>          not for owner-drawn items or additional item-info.  */
Yes I think it is inaccurate.
IMO, GC cannot happen after the build of the widget_value tree is completed.

> If it is inaccurate, why is that?  How is it that GC happens in
> between creation of the widget value and its use in add_menu_item?
> Note that GC ought to be inhibited within set_frame_menubar
> from this line
>
>      inhibit_garbage_collection ();
>
> to this line
>
>      unbind_to (specpdl_count, Qnil);
>
> Does the GC happen inside that range, or after?
> Either way, it's a bug; the question is what bug.
Yes GC seems to happen inside that range when building the widget_value 
tree.
When it happens it can change the address of strings (when compacting 
the string pool)
that are stored in already allocated widget_values.

I suppose it explains this comment

"/* Don't set wv->name here; GC during the loop might relocate it.  */"

which appears inside that range.