Subject: bug#46586: 26.3, 27.1.50; Emacs crash in a backtrace (core) dump (a long standing issue)

From: 路客 <[email-masked]>
Date: Thu, 18 Feb 2021 09:56:06 +0800

> It's an infinite recursion in substitute_object_recurse, called by
> lread--substitute-object-in-subtree.

I see, but why is Emacs 26.0.50 or earlier able to catch this issue?
Shouldn't the read() function try to prevent itself from crashing?