bug#51368: 29.0.50; `cl-case' should error on incorrect use

[Stefan Kangas]

Mattias Engdegård <mattias.engdegard@gmail.com> writes:

>>      (cl-case EXP
>>        ((a b) FOO)
>>        ((a c) BAR))
>>
>>  won't warn about the duplicate `a`.
>
> I was curious how common this could be so I locally added a warning to the 
> back-end in bytecomp that generates switches (attached), and bootstrapped 
> Emacs. Results:
>
> ----------------
> In gnus-cloud-decode-data:
> lisp/gnus/gnus-cloud.el:154:6: Warning: Duplicated value in ‘cond’: 
> base64-gzip
>
> In netrc-parse:
> lisp/obsolete/netrc.el:106:22: Warning: Duplicated value in ‘cond’: "macdef"
>
> In org-read-date-analyze:
> lisp/org/org.el:14041:15: Warning: Duplicated value in ‘cond’: ""
>
> In org-html-latex-fragment:
> lisp/org/ox-html.el:3099:8: Warning: Duplicated value in ‘cond’: t
> -----------------

Thanks, I added FIXMEs for them on master.