bug#47368: 28.0.50; map-elt returns nil without "deprecated" TESTFN

[Michael Heerdegen]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> How 'bout always using `equal`?

I think it would be an improvement.

But are alists the only exception - are we sure there are no useful
implementations of map types were the TESTFN is not constant?  Like a
dictionary where we sometimes want to look up a word case-sensitively,
and if none found, case-insensitively?

Michael.