[Emacs-diffs] master 2139783: nthcdr now works with bignums

[Paul Eggert]

branch: master
commit 21397837eaf0801e7b1cd4155a811a939a7667de
Author: Paul Eggert <address@hidden>
Commit: Paul Eggert <address@hidden>

    nthcdr now works with bignums
    
    Problem reported by Karl Fogel in:
    https://lists.gnu.org/r/emacs-devel/2018-08/msg00671.html
    * src/fns.c (Fnthcdr): Support bignum counts.
---
 src/fns.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/fns.c b/src/fns.c
index a11de1b..aeb9308 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -1402,9 +1402,20 @@ DEFUN ("nthcdr", Fnthcdr, Snthcdr, 2, 2, 0,
        doc: /* Take cdr N times on LIST, return the result.  */)
   (Lisp_Object n, Lisp_Object list)
 {
-  CHECK_FIXNUM (n);
+  CHECK_INTEGER (n);
   Lisp_Object tail = list;
-  for (EMACS_INT num = XFIXNUM (n); 0 < num; num--)
+
+  EMACS_INT num;
+  if (FIXNUMP (n))
+    num = XFIXNUM (n);
+  else
+    {
+      num = mpz_sgn (XBIGNUM (n)->value);
+      if (0 < num)
+       num = EMACS_INT_MAX;  /* LIST cannot possibly be this long.  */
+    }
+
+  for (; 0 < num; num--)
     {
       if (! CONSP (tail))
        {