Hi
Just wanted to report a small bug in org-file-url-p, regarding its use of ffap-url-regexp.
The documentation for ffap-url-regexp states:
Regexp matching the beginning of a URI, for ffap.
If the value is nil, disable URL-matching features in ffap.
I have it set to nil in my setup, to disable url-matching, and this causes org-file-url-p to pass on nil in (string-match-p ffap-url-regexp file), thus causing string-match-p do die with an error.
Othe code in ffap uses and to test the value of ffap-url-regexp before passing it on as in:
(and ffap-url-regexp (string-match-p ffap-url-regexp file))