feature/browse-url-handlers 8046f46: Allow for custom URL handlers in browse-url.

[Tassilo Horn]

branch: feature/browse-url-handlers
commit 8046f46252b5e23a9fa157660efb5c6fc0ea82e2
Author: Tassilo Horn <address@hidden>
Commit: Tassilo Horn <address@hidden>

    Allow for custom URL handlers in browse-url.
    
    * lisp/net/browse-url.el (browse-url-handlers): New defcustom.
    (browse-url): Use it.
---
 lisp/net/browse-url.el | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/lisp/net/browse-url.el b/lisp/net/browse-url.el
index 7aad44b..ab0be7b 100644
--- a/lisp/net/browse-url.el
+++ b/lisp/net/browse-url.el
@@ -175,6 +175,23 @@ Also see `browse-url-secondary-browser-function'."
   :type browse-url--browser-defcustom-type
   :version "24.1")
 
+;;;#autoload
+(defcustom browse-url-handlers
+  `(("\\`mailto:"; . ,browse-url-mailto-function)
+    ("\\`man:" . ,browse-url-man-function))
+  "An alist with elements of the form (REGEXP HANDLER).
+Each REGEXP is matched against each URL to be opened in turn and
+the first match's HANDLER is invoked with the URL.
+
+A HANDLER must either be a function with the same arguments as
+`browse-url' or a variable whos value is such a function.
+
+If no REGEXP matches, the bug reference URL is opened using the
+value of `browse-url-browser-function'."
+  :type '(alist :key-type (regexp :tag "Regexp")
+                :value-type (function :tag "Handler"))
+  :version "28.1")
+
 (defcustom browse-url-secondary-browser-function 'browse-url-default-browser
   "Function used to launch an alternative browser.
 This is usually an external browser (that is, not eww or w3m),
@@ -786,12 +803,14 @@ as ARGS."
              (not (string-match "\\`[a-z]+:" url)))
     (setq url (expand-file-name url)))
   (let ((process-environment (copy-sequence process-environment))
-       (function (or (and (string-match "\\`mailto:"; url)
-                          browse-url-mailto-function)
-                      (and (string-match "\\`man:" url)
-                           browse-url-man-function)
-                     browse-url-browser-function))
-       ;; Ensure that `default-directory' exists and is readable (b#6077).
+       (function
+         (catch 'custom-url-handler
+           (dolist (regex-handler browse-url-handlers)
+             (when (string-match-p (car regex-handler) url)
+               (throw 'custom-url-handler (cdr regex-handler))))
+           ;; No special handler found.
+           browse-url-browser-function))
+       ;; Ensure that `default-directory' exists and is readable (bug#6077).
        (default-directory (or (unhandled-file-name-directory default-directory)
                               (expand-file-name "~/"))))
     ;; When connected to various displays, be careful to use the display of