bug#10940: Emacs 24: regression reading comma

[Chong Yidong]

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

>> In Emacs 23, the lisp reader correctly parses a comma when reading an
>> event modifier, as in the following example specifying the character
>> C-,
>>     (global-set-key [(control ,)] 'my-command)
>
> You did not realize, but the above relies on the old-style backquote
> syntax, which has been further phased out (it's been obsolete for a very
> long time now).  So now (control ,) fails in the same way as (control
> ').  Use [(control ?,)] or [(control \,)] instead (which will work for
> older emacsen as well).

I've added a note to etc/NEWS about this.