bug#31688: 26.1.50; Byte compiler confuses two string variables

[Phil Sainty]

On 2018-06-03 06:02, Noam Postavsky wrote:
> I don't think this is a bug, the compiler coalesces equal string
> literals.

Ouch.  Has this always been the case?  I've been firmly under the
impression that the lisp reader creates a new lisp objects whenever
it reads a string, so it's hugely surprising to me to learn that
(eq str1 str2) can return different results depending on whether
or not the code was byte-compiled.

I see that this is t when compiled and nil otherwise:

(let ((str1 "abc")
      (str2 "abc"))
  (eq str1 str2)))

But this is nil regardless:

(eq "abc" "abc")

This seems kinda horrible?

-Phil