Fix Fnatnump typos

Problem reported by Glenn Morris in:
https://lists.gnu.org/r/emacs-devel/2018-08/msg00946.html
* src/floatfns.c (Fexpt):
* src/xselect.c (cons_to_x_long):
Don't assume Lisp_Object values are scalars.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/xselect.c b/src/xselect.c
index 4b28d474a03..53e788523cc 100644
--- a/src/xselect.c
+++ b/src/xselect.c
@@ -1693,7 +1693,7 @@ static unsigned long
 cons_to_x_long (Lisp_Object obj)
 {
   if (X_ULONG_MAX <= INTMAX_MAX
-      || !Fnatnump (CONSP (obj) ? XCAR (obj) : obj))
+      || NILP (Fnatnump (CONSP (obj) ? XCAR (obj) : obj)))
     return cons_to_signed (obj, X_LONG_MIN, min (X_ULONG_MAX, INTMAX_MAX));
   else
     return cons_to_unsigned (obj, X_ULONG_MAX);