[PATCH] Fix browse-url not working when browse-url-browser-function is a list (regexp . function) pairs

[vibhavp]

If browse-url-browser-function is defined as a list of pairs
(REGEXP . FUNCTION), like:
(setq browse-url-browser-function '(("i\.imgur\.com" browse-url-emacs)
                                    ("." browse-url-chromium)))
browse-url (with an "i.imgur.com" url) will print an error saying that
"(invalid-function (browse-url-chromium))". This is probably because of
how browse-url handles such pairs:

;; The `function' can be an alist; look down it for first match
;; and apply the function (which might be a lambda).
(catch 'done
  (dolist (bf function)
    (when (string-match (car bf) url)
      (apply (cdr bf) url args)
              ^^^^^^ (cdr bf) returns (browse-url-emacs) instead of 
browse-url-emacs
      (throw 'done t)))

This can be easily fixed by replacing "(cdr bf)" with "(cadr bf)". I
have attached a patch which does the same. If it looks good, I'll push
it to master.

diff --git a/lisp/net/browse-url.el b/lisp/net/browse-url.el
index 3f8cb84..fbf2b46 100644
--- a/lisp/net/browse-url.el
+++ b/lisp/net/browse-url.el
@@ -792,7 +792,7 @@ The default is to pass `browse-url-new-window-flag'."
        (catch 'done
          (dolist (bf function)
            (when (string-match (car bf) url)
-             (apply (cdr bf) url args)
+             (apply (cadr bf) url args)
              (throw 'done t)))
          (error "No browse-url-browser-function matching URL %s"
                 url))

Thanks,
Vibhav
-- 
Vibhav Pant
address@hidden