bug#42113: 28.0.50; Segmentation fault in json-parse-file

[Eli Zaretskii]

On June 29, 2020 11:33:45 AM GMT+03:00, Philipp Stephani 
<p.stephani2@gmail.com> wrote:
> Am So., 28. Juni 2020 um 23:53 Uhr schrieb Erik Hetzner <egh@e6h.org>:
> >
> > 1. Start emacs -Q
> > 2. Evaluate the following
> > (require 'dom)
> >
> > (with-current-buffer (url-retrieve-synchronously
> "https://www.seriouseats.com/recipes/2020/06/florentine-omelette-spinach-and-cheese.html";)
> >         (let* ((dom (libxml-parse-html-region (point-min)
> (point-max)))
> >                (scripts (dom-by-tag dom 'script))
> >                (json-lds-raw (dom-elements scripts 'type
> "^application/ld\\+json$"))
> >                (json-lds (mapcar #'json-parse-string
> json-lds-raw)))))
> >
> > Result: segmentation fault.
> 
> Simpler: (json-parse-string 1)
> The JSON functions are missing CHECK_STRING in several places where
> json_encode is called.

In this specific case I think the test is there, but it is done a bit too late. 
 The call to check_string_without_embedded_nuls should be moved before 
json_encode.