Avoid trashing arguments before we've used them.

[u/mdw/catacomb] / mpmont.c

diff --git a/mpmont.c b/mpmont.c
index 2371de8..c644801 100644 (file)
--- a/mpmont.c
+++ b/mpmont.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: mpmont.c,v 1.15 2001/06/16 13:00:20 mdw Exp $
+ * $Id: mpmont.c,v 1.16 2002/01/13 13:40:31 mdw Exp $
  *
  * Montgomery reduction
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: mpmont.c,v $
+ * Revision 1.16  2002/01/13 13:40:31  mdw
+ * Avoid trashing arguments before we've used them.
+ *
  * Revision 1.15  2001/06/16 13:00:20  mdw
  * Use the generic exponentiation functions.
  *
@@ -408,9 +411,11 @@ mp *mpmont_expr(mpmont *mm, mp *d, mp *a, mp *e)
 
 mp *mpmont_exp(mpmont *mm, mp *d, mp *a, mp *e)
 {
+  e = MP_COPY(e);
   d = mpmont_mul(mm, d, a, mm->r2);
   d = mpmont_expr(mm, d, d, e);
   d = mpmont_reduce(mm, d, d);
+  MP_DROP(e);
   return (d);
 }