[newlib-cygwin] Cygwin: serial: wait for CancelIo completion

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=7947581905637b837558ae9a2f1d35b8ab433e90

commit 7947581905637b837558ae9a2f1d35b8ab433e90
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Mon Mar 16 10:20:16 2020 +0100

    Cygwin: serial: wait for CancelIo completion
    
    Per https://devblogs.microsoft.com/oldnewthing/20110202-00/?p=11613
    GetOverlappedResult must be called blocking, waiting for the overlapped
    operation to complete.
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/fhandler_serial.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/cygwin/fhandler_serial.cc b/winsup/cygwin/fhandler_serial.cc
index f92fc7039..f729765e0 100644
--- a/winsup/cygwin/fhandler_serial.cc
+++ b/winsup/cygwin/fhandler_serial.cc
@@ -135,7 +135,7 @@ fhandler_serial::raw_read (void *ptr, size_t& ulen)
 	     PurgeComm apparently discards in-flight bytes while CancelIo
 	     only stops the overlapped IO routine. */
 	  CancelIo (get_handle ());
-	  if (GetOverlappedResult (get_handle (), &io_status, &n, FALSE))
+	  if (GetOverlappedResult (get_handle (), &io_status, &n, TRUE))
 	    tot = n;
 	  else if (GetLastError () != ERROR_OPERATION_ABORTED)
 	    goto err;