* path.cc (path_conv::check): Don't complain if /dev/x/foo when x doesn't

exist.
(mount_info::conv_to_win32_path): Keep translating when a /cygdrive is found.
Don't attempt to translate to a device name when devn == FH_CYGDRIVE.
(cygwin_conv_to_win32_path): Set buffer to empty on error.
(cygwin_conv_to_full_win32_path): Ditto.
* window.cc: Include unistd.h to verify definitions.

winsup/cygwin/window.cc

@@ -18,6 +18,7 @@ details. */
 #include <limits.h>
 #include <wingdi.h>
 #include <winuser.h>
+#include <unistd.h>
 #include "cygerrno.h"
 #include "perprocess.h"
 #include "security.h"