[Bug 10056] New: False error on serial port read

http://bugs.winehq.org/show_bug.cgi?id=10056

Summary: False error on serial port read
           Product: Wine
           Version: CVS/GIT
          Platform: PC
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P2
         Component: wine-kernel
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

Created an attachment (id=8604)
 --> (http://bugs.winehq.org/attachment.cgi?id=8604)
An internal hack used to work around the problem.

We use an application which reads from a serial port or emulated serial port.
This stopped working with recent versions of Wine, and bisection tracked it
down to this commit:

http://source.winehq.org/git/wine.git/?a=commitdiff;h=539d5863e6fae78943fe59...

This commit makes NtReadFile() return STATUS_PIPE_BROKEN whenever the read()
system call returns 0. Unfortunately, Wine sets VMIN to 0, forcing read() to
return 0 whenever there is no data available:

http://source.winehq.org/source/dlls/ntdll/serial.c#L752

Our application sees STATUS_PIPE_BROKEN, and immediately fails.

I've attached a patch which we use to work around this problem, but I'd like to
work towards a more elegant solution.