bug#33765: emacs-26.1-mac-7.4; (expt 2 140) ; produces 0 in scratch buffer, unexpectedly

[Van L]

>>> Why do you say this is unexpected?
>> 
>> I am not a mathematician but I believe the answer is wrong for 2^140.
> 
> The correct value cannot be represented in an Emacs fixnum.  What did you 
> expect Emacs to do?  IOW, what would be the "expected" result, given the 
> limited range of integers we can represent?

I expect no answer and an error out with an informative explanation if asked 
for, when Emacs is unable to do.

>>> If you want the same support for huge numbers as in Scheme, try
>> Emacs 27.
>> 
>> I take that to mean the master branch but the emacs-mac repo-updates
>> are less freq. than gnu-emacs’s.
> 
> Some features, such as this one, will not be available in older versions.

A helpful place to explain the versioning policy would be a file in the 
emacs/etc directory.

Version 26 means stable, 27 means unstable is my guess.