forgot to check for 0

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@2989 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 10 insertions, 4 deletions

diff --git a/get_ui.c b/get_ui.c
index 0b42a90a8..1d5d286d0 100644
--- a/get_ui.c
+++ b/get_ui.c
@@ -40,10 +40,16 @@ mpfr_get_ui (mpfr_srcptr f, mp_rnd_t rnd)
   mpfr_init2 (x, prec);
   mpfr_rint (x, f, rnd);
 
-  /* now the result is in the most significant limb of x */
-  exp = MPFR_GET_EXP (x); /* since |x| >= 1, exp >= 1 */
-  n = MPFR_LIMB_SIZE(x);
-  s = MPFR_MANT(x)[n - 1] >> (BITS_PER_MP_LIMB - exp);
+  /* warning: if x=0, taking its exponent is illegal */
+  if (MPFR_IS_ZERO(x))
+    s = 0;
+  else
+    {
+      /* now the result is in the most significant limb of x */
+      exp = MPFR_GET_EXP (x); /* since |x| >= 1, exp >= 1 */
+      n = MPFR_LIMB_SIZE(x);
+      s = MPFR_MANT(x)[n - 1] >> (BITS_PER_MP_LIMB - exp);
+    }
 
   mpfr_clear (x);