bug#18510: 24.4.50; ERC doesn't update mode line frequently enough

[Stefan Monnier]

>> I've worked around it locally by advising erc-update-mode-line to call
>> (force-mode-line-update t).
> That's not a workaround, that's a fix.

Hmm... not sure what that was about, sorry.  Of course, the
(force-mode-line-update t) should only be called when changing
a variable that's visible in the global mode-line-format.

Does the patch below work?
[ I assume the problem is also present in 24.3.93.  ]


        Stefan


=== modified file 'lisp/erc/erc-track.el'
--- lisp/erc/erc-track.el       2014-02-10 01:34:22 +0000
+++ lisp/erc/erc-track.el       2014-09-19 18:34:57 +0000
@@ -767,8 +765,7 @@
                  (erc-modified-channels-remove-buffer buffer))))
            erc-modified-channels-alist)
       (when removed-channel
-       (erc-modified-channels-display)
-       (force-mode-line-update t)))
+       (erc-modified-channels-display)))
     (remove-hook 'post-command-hook 'erc-modified-channels-update)))
 
 (defvar erc-track-mouse-face (if (featurep 'xemacs)
@@ -825,9 +822,10 @@
        ((eq 'importance erc-track-switch-direction)
         (erc-track-sort-by-importance)))
   (run-hooks 'erc-track-list-changed-hook)
-  (unless (eq erc-track-position-in-mode-line nil)
-  (if (null erc-modified-channels-alist)
-      (setq erc-modified-channels-object (erc-modified-channels-object nil))
+  (when erc-track-position-in-mode-line
+    (let* ((oldobject erc-modified-channels-object)
+          (strings
+           (when erc-modified-channels-alist
     ;; erc-modified-channels-alist contains all the data we need.  To
     ;; better understand what is going on, we split things up into
     ;; four lists: BUFFERS, COUNTS, SHORT-NAMES, and FACES.  These
@@ -858,10 +856,11 @@
              buffers (cdr buffers)
              counts (cdr counts)
              faces (cdr faces)))
-      (when (featurep 'xemacs)
-       (erc-modified-channels-object nil))
-      (setq erc-modified-channels-object
-           (erc-modified-channels-object strings))))))
+               strings)))
+          (newobject (erc-modified-channels-object strings)))
+      (unless (equal oldobject newobject)
+       (setq erc-modified-channels-object newobject)
+       (force-mode-line-update t)))))
 
 (defun erc-modified-channels-remove-buffer (buffer)
   "Remove BUFFER from `erc-modified-channels-alist'."