Showing urgent (flashing) windows on all desktop in LXDE’s taskbar (window list) in Lubuntu

As it stands, lxpanel’s taskbar plugin (part of the LXDE desktop you get with Lubuntu) does not show urgent (flashing) windows if they are on a different virtual desktop from the one you are looking at.

This seems wrong to me (I logged Bug 682), and the fix is a little one-liner:

--- lxpanel.orig/src/plugins/taskbar.c  2013-08-27 23:57:55.000000000 +0100
+++ lxpanel/src/plugins/taskbar.c       2014-09-26 00:48:25.026855589 +0100
@@ -202,10 +202,10 @@
     tk->flash_timeout = g_timeout_add(interval, (GSourceFunc) flash_window_timeout, tk);
 }
 
-/* Determine if a task is visible considering only its desktop placement. */
+/* Determine if a task is visible considering only its desktop placement and urgency. */
 static gboolean task_is_visible_on_current_desktop(TaskbarPlugin * tb, Task * tk)
 {
-    return ((tk->desktop == ALL_WORKSPACES) || (tk->desktop == tb->current_desktop) || (tb->show_all_desks));
+    return ((tk->desktop == ALL_WORKSPACES) || (tk->desktop == tb->current_desktop) || (tb->show_all_desks) || tk->urgency);
 }
 
 /* Recompute the visible task for a class when the class membership changes.

To install this patch into Lubuntu, do something like this:

sudo apt-get install build-essential fakeroot dpkg-dev
sudo apt-get build-dep lxpanel
mkdir lxpanel
cd lxpanel
apt-get source lxpanel
cd lxpanel-*
wget https://sourceforge.net/p/lxde/bugs/682/attachment/show-urgent-windows-on-all-desktops.patch
patch -p1 < show-urgent-windows-on-all-desktops.patch
dpkg-buildpackage -rfakeroot -b
cd ..
sudo dpkg -i lxpanel_*.deb
killall lxpanel
lxpanel --profile Lubuntu