bug#46811: 27.1; json-pretty-print fails if there is a map with "t" as one of the keys

[Eli Zaretskii]

> From: Anantha Kumaran <ananthakumaran@gmail.com>
> Date: Sat, 27 Feb 2021 12:19:01 +0530
> 
> mark the json text below and run M-x json-pretty-print
> 
>   {"t": "hello"}
> 
> Debugger entered--Lisp error: (json-key-format t)
>   signal(json-key-format (t))
>   json-pretty-print(1 15 nil)
>   funcall-interactively(json-pretty-print 1 15 nil)
>   call-interactively(json-pretty-print record nil)
>   command-execute(json-pretty-print record)
>   execute-extended-command(nil "json-pretty-print" "json")
>   funcall-interactively(execute-extended-command nil "json-pretty-print" 
> "json")
>   call-interactively(execute-extended-command nil nil)
>   command-execute(execute-extended-command)

Thanks, this is already fixed in the development sources, which will
become Emacs 28.