Fix (round FLOAT BIGNUM) bug

* src/floatfns.c (rounding_driver): Fix bug when one
argument is a float and the other is a bignum.
* test/src/floatfns-tests.el (bignum-round): Test for the bug.

1 files changed, 5 insertions, 0 deletions

diff --git a/test/src/floatfns-tests.el b/test/src/floatfns-tests.el
index d41b08f7965..9a382058b43 100644
--- a/test/src/floatfns-tests.el
+++ b/test/src/floatfns-tests.el
@@ -70,6 +70,11 @@
       (should (= n (floor n)))
       (should (= n (round n)))
       (should (= n (truncate n)))
+      (let ((-n (- n))
+            (f (float n))
+            (-f (- (float n))))
+        (should (= 1 (round n f) (round -n -f) (round f n) (round -f -n)))
+        (should (= -1 (round -n f) (round n -f) (round f -n) (round -f n))))
       (dolist (d ns)
         (let ((q (/ n d))
               (r (% n d))