compat/win32/poll.c: upgrade from upstream

poll.c is updated from revision adc3a5b in
git://git.savannah.gnu.org/gnulib.git

The changes are applied with --whitespace=fix to reduce noise.

poll.h is not upgraded, because the most recent version now
contains template-stuff that breaks compilation for us.
Signed-off-by: NErik Faye-Lund <kusmabite@gmail.com>
Acked-by: NJohannes Sixt <j6t@kdbg.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

compat/win32/poll.c

 /* Emulation for poll(2)
    Contributed by Paolo Bonzini.
 
-   Copyright 2001-2003, 2006-2010 Free Software Foundation, Inc.
+   Copyright 2001-2003, 2006-2011 Free Software Foundation, Inc.
 
    This file is part of gnulib.
 
@@ -27,7 +27,10 @@
 #include <malloc.h>
 
 #include <sys/types.h>
-#include "poll.h"
+
+/* Specification.  */
+#include <poll.h>
+
 #include <errno.h>
 #include <limits.h>
 #include <assert.h>
@@ -314,10 +317,7 @@ compute_revents (int fd, int sought, fd_set *rfds, fd_set *wfds, fd_set *efds)
 #endif /* !MinGW */
 
 int
-poll (pfd, nfd, timeout)
-     struct pollfd *pfd;
-     nfds_t nfd;
-     int timeout;
+poll (struct pollfd *pfd, nfds_t nfd, int timeout)
 {
 #ifndef WIN32_NATIVE
   fd_set rfds, wfds, efds;
@@ -454,6 +454,7 @@ poll (pfd, nfd, timeout)
   if (!hEvent)
     hEvent = CreateEvent (NULL, FALSE, FALSE, NULL);
 
+restart:
   handle_array[0] = hEvent;
   nhandles = 1;
   FD_ZERO (&rfds);
@@ -594,6 +595,12 @@ poll (pfd, nfd, timeout)
 	rc++;
     }
 
+  if (!rc && timeout == INFTIM)
+    {
+      SwitchToThread();
+      goto restart;
+    }
+
   return rc;
 #endif
 }