Re: browse-url-firefox

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 05 Jan 2008 18:31:22 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: emacs-devel@gnu.org
> 
> 	  (apply 'start-process
> 		 (concat "firefox " url) nil
> 		 browse-url-firefox-program
> 		 (append
> 		  browse-url-firefox-arguments
> 		  (if (or (featurep 'dos-w32)
> 			  (string-match "win32" system-configuration))
> 		      (list url)
> 		    (list "-remote"
> 			  (concat "openURL("
> 				  url
> 				  (if (browse-url-maybe-new-window
> 				       new-window)
> 				      (if browse-url-firefox-new-window-is-tab
> 					  ",new-tab"
> 					",new-window"))
> 				  ")")))))))
> 
> has the effect of invoking Firefox with the URL specified twice on the
> command line (so Firefox opens it in two tabs).  I think it's a bug,
> and that the right fix is to not (concat "firefox " url), but to use a
> literal "firefox" instead.  Does anyone see where I'm wrong?
> 
> Steve, do you have any objections to such a change?

Also, why do we need to set up a process-sentinel in this case?
Here's the relevant fragments from browse-url:

       (set-process-sentinel process
			     `(lambda (process change)
				(browse-url-firefox-sentinel process ,url)))))

   (defun browse-url-firefox-sentinel (process url)
     "Handle a change to the process communicating with Firefox."
     (or (eq (process-exit-status process) 0)
	 (let* ((process-environment (browse-url-process-environment)))
	   ;; Firefox is not running - start it
	   (message "Starting Firefox...")
	   (apply 'start-process (concat "firefox " url) nil
		  browse-url-firefox-program
		  (append browse-url-firefox-startup-arguments (list url))))))

At least on MS-Windows, when an instance of Firefox is already
running, invoking another one like "firefox http://foo.bar" has the
effect of asking the first instance of Firefox to display
http://foo.bar in another tab, and the second Firefox exits
immediately.  So the above sentinel has 2 adverse effects: (1) it
opens http://foo.bar twice, because the sentinel is invoked when the
second instance of Firefox exits, and (2) the sentinel is invoked if I
close Firefox by via the window manager, at which time the sentinel
starts Firefox again with the last URL I browsed.

Is the behavior of Firefox on other platforms different?

I think the right fix for this is to set-process-sentinel to nil.  Any
objections?