MFC 198990: Several years ago a feature was added to TCP that casued soreceive() to send an ACK right away if data was drained from a TCP socket that had previously advertised a zero-sized window.  The current code requires the receive window to be exactly zero for this to kick in.  If window scaling is enabled and the window is smaller than the scale, then the effective window that is advertised is zero.  However, in that case the zero-sized window handling is not enabled because the window is not exactly zero.  The fix changes the code to check the raw window value against zero.
MFC 198990:
Several years ago a feature was added to TCP that casued soreceive() to
send an ACK right away if data was drained from a TCP socket that had
previously advertised a zero-sized window.  The current code requires the
receive window to be exactly zero for this to kick in.  If window scaling is
enabled and the window is smaller than the scale, then the effective window
that is advertised is zero.  However, in that case the zero-sized window
handling is not enabled because the window is not exactly zero.  The fix
changes the code to check the raw window value against zero.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase