[Bug 49986] New: Missing SIO_IDEAL_SEND_BACKLOG_QUERY in WinSCP, Overwatch et al.

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=49986

Bug ID: 49986
           Summary: Missing SIO_IDEAL_SEND_BACKLOG_QUERY in WinSCP,
                    Overwatch et al.
           Product: Wine
           Version: 5.19
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: winsock
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

When using WinSCP 5.17.7 and connecting to a SFTP server, Wine write the
following log lines into ~/.xsession_errors every second.

01bc:fixme:winsock:server_ioctl_sock Unsupported ioctl 4004747b (device=4004
access=1 func=d1e method=3)
01bc:fixme:winsock:WSAIoctl unsupported WS_IOCTL cmd
(SIO_IDEAL_SEND_BACKLOG_QUERY)

This is due to WinSCP querying an ideal connection buffer size via
SIO_IDEAL_SEND_BACKLOG_QUERY once per second:
https://docs.microsoft.com/en-us/previous-versions/windows/desktop/legacy/bb...)

A quick search revealed that these errors also occur in Overwatch.