kernel32: Always set bytes written in WriteFile.

dlls/kernel32/file.c

@@ -577,8 +577,8 @@ BOOL WINAPI WriteFile( HANDLE hFile, LPCVOID buffer, DWORD bytesToWrite,
         status = piosb->u.Status;
     }
 
-    if (status != STATUS_PENDING && bytesWritten)
-        *bytesWritten = piosb->Information;
+    if (bytesWritten)
+        *bytesWritten = overlapped && status ? 0 : piosb->Information;
 
     if (status && status != STATUS_TIMEOUT)
     {

dlls/kernel32/tests/pipe.c

@@ -2767,7 +2767,7 @@ static void _overlapped_write_async(unsigned line, HANDLE writer, void *buf, DWO
     overlapped->hEvent = CreateEventW(NULL, TRUE, FALSE, NULL);
     res = WriteFile(writer, buf, size, &written_bytes, overlapped);
     ok_(__FILE__,line)(!res && GetLastError() == ERROR_IO_PENDING, "WriteFile returned %x(%u)\n", res, GetLastError());
-    todo_wine ok_(__FILE__,line)(!written_bytes, "written_bytes = %u\n", written_bytes);
+    ok_(__FILE__,line)(!written_bytes, "written_bytes = %u\n", written_bytes);
 
     _test_not_signaled(line, overlapped->hEvent);
 }