GetDriveType and empty CD/DVD-ROM drives

[GOUJON Alexandre]

Hi,

I'm currently working on bug #17037.
The root cause is that GetDriveType("D:\") (if D is mapped to 
/dev/cdrom) returns DRIVE_NO_ROOT_DIR while on Windows it returns 
DRIVE_CDROM when there is no disc in the D drive.

GetDriveType tries to open D:\ which is converted into \\??\\D:\\ then 
~/.wine/dosdevices/d:/
The fact is that there is a dosdevices/d:: file (symlinked to 
/dev/cdrom) but no dosdevices/d: except if a CD or DVD is in and mounted 
somewhere.

The conversion \\??\\D:\\ -> ~/.wine/dosdevices/d:/ is done in 
wine_nt_to_unix_file_name (ntdll/directory.c, line 2897).
I'm asking here because I wonder if modifying wine_nt_to_unix_file_name 
is the right thing to do and sane: it's called at several locations and 
I don't want to cause trouble and regressions, well, if possible.

Thanks for any advice