http://bugs.winehq.org/show_bug.cgi?id=18192
--- Comment #13 from Dmitry Timoshkov dmitry@codeweavers.com 2009-04-27 08:52:11 --- (In reply to comment #12)
You can use the hook to store the desired encoding when saving, I don't see any reason to detect the file encoding
This is so that when you click on a file in the Open dialog, the encoding is detected automatically, and the drop down box is set to it (this can then be overridden by the user). In the Save As dialog, the encoding box shouldn't be changed by clicking on different files.
Then, yes, I don't see another way to do that, so your solution is OK.