http://bugs.winehq.org/show_bug.cgi?id=13303
--- Comment #3 from Vincent Povirk madewokherd@gmail.com 2008-05-18 20:59:23 --- Created an attachment (id=13165) --> (http://bugs.winehq.org/attachment.cgi?id=13165) patch to escape things for .desktop files more
This patch seems to solve the issue.
From the Desktop Entry spec, it appears \\ is the correct way to represent a
\ in the Exec field, whether the \ happens to be in quotation marks or not. For some reason, \ happens to result in a \ sent to the program if it happens to be in quotes, but it's not clear whether this is reliable behavior, and it does not happen outside of the quotes.