[Bug 23378] New: Desktop launchers generated by new Steam UI are broken

http://bugs.winehq.org/show_bug.cgi?id=23378

Summary: Desktop launchers generated by new Steam UI are broken
           Product: Wine
           Version: 1.2-rc4
          Platform: x86
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: shell32
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

After upgrading Steam to the new UI, the application icons Steam generates on
the desktop are broken. They don't have an icon attached, the icon is not
written to $HOME/.local/share/icons, and the launch command doesn't work with
Wine, because the steam URL handler isn't registered (at least in GNOME):

[Desktop Entry]
Name=Uplink
Exec=env WINEPREFIX="/home/user/.wine" wine winebrowser steam://rungameid/6910
Type=Application
StartupNotify=true

$ wine winebrowser steam://rungameid/1510
fixme:ntoskrnl:KeInitializeTimerEx stub: 0x110f60 0
gvfs-open: steam://rungameid/1510: error opening location: La ubicación
especificada no está soportada
(That translates to "unsupported location.")

A desktop file generated with the older UI looks like this, has the correct
icon, and launches the game fine:

#!/usr/bin/env xdg-open
[Desktop Entry]
Name=Deus Ex Game of the Year Edition
Exec=env WINEPREFIX="/home/user/.wine" wine "C:\Archivos de
programa\Steam\steam.exe" -applaunch 6910
Type=Application
StartupNotify=true
Path=/home/user/.wine/dosdevices/c:/Archivos de programa/Steam
Icon=/home/user/.local/share/icons/b45c_hdtp.png