http://bugs.winehq.org/show_bug.cgi?id=30618
--- Comment #2 from Stephan Sokolow from_wine_bugzilla@ssokolow.com 2012-05-08 07:37:00 CDT --- I'll keep it in mind in case I can spare the time.
Since, once my exam study is over, I plan to provide "just change this to that" solutions in the bug reports I file on various Java apps and on WinPDB, I'll probably need to implement something like this for Java and wxPython apps anyway. If/when I do, porting it for use in Wine probably wouldn't be too difficult.
Obviously a fallback would be important. My plan was to do something along the lines of how fallback can be handled in QIcon::fromTheme and just keep the existing icon lookup around as the fallback.
As for writing up a mapping table, that's actually the one kind of drudge-work I don't mind when I do it on my own initiative.
Thanks for mentioning xsettings. How you look up the name of the currently active icon theme is the one glaring detail not included in the pseudocode in the XDG icon theme spec.