[Bug 19778] New: cmd set "FOO=bar" does the wrong thing; breaks firefox build script

http://bugs.winehq.org/show_bug.cgi?id=19778

Summary: cmd set "FOO=bar" does the wrong thing; breaks firefox
                    build script
           Product: Wine
           Version: 1.1.27
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: programs
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

The firefox build scripts do

SET "PATH=%PATH%;%MOZ_TOOLS%\bin"

On Wine, this sets the bizarre environment variable "PATH.