On Oct 26, 2022, 10:00 AM -0600, Eli Zaretskii <eliz@gnu.org>, wrote:
Date: Wed, 26 Oct 2022 09:40:30 -0600
From: Troy Hinckley <troyhinckley@gmail.com>
I have been reading through the C source to try and learn it and understand it better. I saw in Changeling.13 an
entry From Paul Eggert on 2015-01-05 with “Use 0 for Qnil” As a fix for Bug#15880. How does this work in
practice? It looks like symbols are just pointers, but 0 would not be a valid pointer. I don’t see any special code
for handling the null case.
Symbols are not pointers, they have the same C type as any other
Lisp_Object. If Lisp_Object is represented by an integer number, then
zero is a valid integer number as well.