https://bugs.winehq.org/show_bug.cgi?id=38115
--- Comment #6 from Matteo Bruni matteo.mystral@gmail.com --- Actually it's pretty clear, thanks Christian for the thorough analysis.
Wine does also look for the short filenames, the problem is that it uses an incompatible encoding (e.g. see http://source.winehq.org/git/wine.git/blob/370254cbe93beae6a9ff693d98c638db5...), probably because it has to generate unambiguous short names without storing them on the filesystem. What it means is that Wine is okay if e.g. an application creates a file with a long name and then looks up the short name version but it fails in this case since the file was created and is stored with the "windows version" short name.
I guess this bug could be fixed by e.g. storing the short filenames in extended attributes and then using a compatible short filename encoding. Not trivial but if you want to take a stab at it it would be great ;)