Thunderbird (OK, "Icedove") has no icon in task-switching panel in Xfce

[Carl Fink <carlf@panix.com>]

My, that's a small, specific question I'm asking.

I'm running Icedove 1:45.8.0-2 (which is really Thunderbird 1:45.8.0-2) 
under Debian testing, with
Xfce 4.12.3 as my desktop environment. It works fine (modulo the fact 
that I don't like every tbird
design decision, but it works as designed), except for one very small 
thing: when I task-switch
using alt-tab, the icon for Thunderbird is the 
empty-white-window-with-blue-title-bar icon, which
I'm presuming is the default for "this program has not defined an icon". 
That's also the icon that
appears in the workspace indicator in the Xfce4 panel.

Is this a bug? Are others seeing this? It is not a huge deal, but it's 
annoying because I always
task-switch with alt-tab and finding Thunderbird is harder when it has a 
nondistinctive icon that
does not match the one in its button on the main Xfce panel.

Thanks.
--
Carl Fink          carl@finknetwork.com
Writing about thinking and logic and stuff at Reasonably Literate
http://reasonablyliterate.com