[Bug 51950] New: Iperf 2.0.8 hangs in parallel dual mode on localhost

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=51950

Bug ID: 51950
           Summary: Iperf 2.0.8 hangs in parallel dual mode on localhost
           Product: Wine
           Version: 6.20
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: winsock
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

I found a problem in Wine winsock that may also be related to bug 51442 but I'm
opening a new bug report since this is not a regression.

On Windows, it is possible to run iperf 2.0.8 in dual mode on localhost in
parallel mode, so the following command works:

iperf -c 127.0.0.1 -d -t 1 -P 5

However, the same command freezes iperf completely on Wine, few messages
"connect failed: Connection refused" appear and Ctrl+C for terminating iperf
does not work.

This behavior is valid for all Wine versions (tested on 6.0.2, 6.11 and 6.20).