tst_QSocks5SocketEngine::downloadBigFile() is flaky

 Mingw32-make[1]: Entering directory 'C:/Users/qt/work/qt/qtbase/tests/auto/network/socket/qsocks5socketengine'
 call C:\Users\qt\work\qt\qtbase\tests\auto\network\socket\qsocks5socketengine\target_wrapper.bat  release\tst_qsocks5socketengine.exe -o c:\Users\qt\work\testresults\tests\auto\network\socket\qsocks5socketengine517199815,xml -o -,txt
 ********* Start testing of tst_QSocks5SocketEngine *********
 Config: Using QtTest library 5.9.1, Qt 5.9.1 (i386-little_endian-ilp32 shared (dynamic) release build; by GCC 5.3.0)
 PASS   : tst_QSocks5SocketEngine::initTestCase()
 PASS   : tst_QSocks5SocketEngine::construction()
 PASS   : tst_QSocks5SocketEngine::errorTest(proxy-host-not-found)
 PASS   : tst_QSocks5SocketEngine::errorTest(proxy-connection-refused)
 PASS   : tst_QSocks5SocketEngine::errorTest(garbage1)
 PASS   : tst_QSocks5SocketEngine::errorTest(garbage2)
 PASS   : tst_QSocks5SocketEngine::errorTest(unknown-auth-method)
 PASS   : tst_QSocks5SocketEngine::errorTest(no-acceptable-authentication)
 PASS   : tst_QSocks5SocketEngine::errorTest(authentication-required)
 PASS   : tst_QSocks5SocketEngine::errorTest(connection-not-allowed)
 PASS   : tst_QSocks5SocketEngine::errorTest(network-unreachable)
 PASS   : tst_QSocks5SocketEngine::errorTest(host-unreachable)
 PASS   : tst_QSocks5SocketEngine::errorTest(connection-refused)
 PASS   : tst_QSocks5SocketEngine::simpleConnectToIMAP()
 PASS   : tst_QSocks5SocketEngine::simpleErrorsAndStates()
 BFAIL  : tst_QSocks5SocketEngine::udpTest() 'udpSocket.waitForRead()' returned FALSE. ()
 tst_qsocks5socketengine.cpp(545) : failure location
 BPASS  : tst_QSocks5SocketEngine::serverTest()
 PASS   : tst_QSocks5SocketEngine::tcpSocketBlockingTest()
 PASS   : tst_QSocks5SocketEngine::tcpSocketNonBlockingTest()
 QWARN  : tst_QSocks5SocketEngine::downloadBigFile() downloadBigFile: error QAbstractSocket::RemoteHostClosedError: The remote host closed the connection
 FAIL!  : tst_QSocks5SocketEngine::downloadBigFile() Compared values are not the same
    Actual   (socket.state())                 : UnconnectedState
    Expected (QAbstractSocket::ConnectedState): ConnectedState
 tst_qsocks5socketengine.cpp(777) : failure location
 QWARN  : tst_QSocks5SocketEngine::passwordAuth() QAbstractSocket::connectToHost() called when already looking up or connecting/connected to "qt-test-server.qt-test-net"
 QDEBUG : tst_QSocks5SocketEngine::passwordAuth() 19, Trying to connect while connection is in progress
 BPASS  : tst_QSocks5SocketEngine::passwordAuth()
 QWARN  : tst_QSocks5SocketEngine::passwordAuth2() QAbstractSocket::connectToHost() called when already looking up or connecting/connected to "qt-test-server.qt-test-net"
 PASS   : tst_QSocks5SocketEngine::passwordAuth2()
 PASS   : tst_QSocks5SocketEngine::fragmentation(auth-method)
 PASS   : tst_QSocks5SocketEngine::fragmentation(auth-response)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv4-1)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv4-2)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv4-3)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv4-4)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv4-5)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv4-6)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv4-7)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv4-8)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-1)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-2)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-3)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-4)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-5)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-6)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-7)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-8)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-9)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-10)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-11)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-12)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-13)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-14)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-15)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-16)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-17)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-18)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-19)
 PASS   : tst_QSocks5SocketEngine::fragmentation(connect-response-ipv6-20)
 PASS   : tst_QSocks5SocketEngine::incomplete(auth-method)
 PASS   : tst_QSocks5SocketEngine::incomplete(auth-response)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv4-1)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv4-2)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv4-3)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv4-4)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv4-5)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv4-6)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv4-7)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv4-8)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-1)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-2)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-3)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-4)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-5)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-6)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-7)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-8)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-9)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-10)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-11)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-12)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-13)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-14)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-15)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-16)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-17)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-18)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-19)
 PASS   : tst_QSocks5SocketEngine::incomplete(connect-response-ipv6-20)
 PASS   : tst_QSocks5SocketEngine::cleanupTestCase()
 Totals: 79 passed, 1 failed, 0 skipped, 3 blacklisted, 66006ms
 ********* Finished testing of tst_QSocks5SocketEngine *********
bat  release\tst_qsocks5socketengine.exe downloadBigFile
 ********* Start testing of tst_QSocks5SocketEngine *********
 Config: Using QtTest library 5.9.1, Qt 5.9.1 (i386-little_endian-ilp32 shared (dynamic) release build; by GCC 5.3.0)
 PASS   : tst_QSocks5SocketEngine::initTestCase()
 PASS   : tst_QSocks5SocketEngine::downloadBigFile()
 PASS   : tst_QSocks5SocketEngine::cleanupTestCase()
 Totals: 3 passed, 0 failed, 0 skipped, 0 blacklisted, 2687ms
 ********* Finished testing of tst_QSocks5SocketEngine *********
C:\Users\qt\work\qt\qtbase\tests\auto\network\socket\qsocks5socketengine\target_wrapper.bat  release\tst_qsocks5socketengine.exe downloadBigFile
 ********* Start testing of tst_QSocks5SocketEngine *********
 Config: Using QtTest library 5.9.1, Qt 5.9.1 (i386-little_endian-ilp32 shared (dynamic) release build; by GCC 5.3.0)
 PASS   : tst_QSocks5SocketEngine::initTestCase()
 QWARN  : tst_QSocks5SocketEngine::downloadBigFile() [     0.000 W] default unknown - downloadBigFile: error QAbstractSocket::RemoteHostClosedError: The remote host closed the connection
 FAIL!  : tst_QSocks5SocketEngine::downloadBigFile() Compared values are not the same
    Actual   (socket.state())                 : UnconnectedState
    Expected (QAbstractSocket::ConnectedState): ConnectedState
 tst_qsocks5socketengine.cpp(777) : failure location
 PASS   : tst_QSocks5SocketEngine::cleanupTestCase()
 Totals: 2 passed, 1 failed, 0 skipped, 0 blacklisted, 2384ms
 ********* Finished testing of tst_QSocks5SocketEngine *********