[src/eint.c] Fixed eint(-inf).

[tests/teint.c] Added a corresponding test.

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@10008 280ebfd0-de03-0410-8827-d642c229c3f4

2 files changed, 14 insertions, 4 deletions

diff --git a/src/eint.c b/src/eint.c
index a32d71a49..02f1f3b39 100644
--- a/src/eint.c
+++ b/src/eint.c
@@ -212,16 +212,18 @@ mpfr_eint (mpfr_ptr y, mpfr_srcptr x, mpfr_rnd_t rnd)
 
   if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (x)))
     {
-      /* exp(NaN) = exp(-Inf) = NaN */
-      if (MPFR_IS_NAN (x) || (MPFR_IS_INF (x) && MPFR_IS_NEG(x)))
+      if (MPFR_IS_NAN (x))
         {
           MPFR_SET_NAN (y);
           MPFR_RET_NAN;
         }
-      /* eint(+inf) = +inf */
       else if (MPFR_IS_INF (x))
         {
-          MPFR_SET_INF(y);
+          /* eint(+inf) = +inf and eint(-inf) = +0 */
+          if (MPFR_IS_POS (x))
+            MPFR_SET_INF(y);
+          else
+            MPFR_SET_ZERO(y);
           MPFR_SET_POS(y);
           MPFR_RET(0);
         }
diff --git a/tests/teint.c b/tests/teint.c
index aa8d513a3..4a29eec01 100644
--- a/tests/teint.c
+++ b/tests/teint.c
@@ -49,6 +49,14 @@ check_specials (void)
       exit (1);
     }
 
+  mpfr_set_inf (x, -1);
+  mpfr_eint (y, x, MPFR_RNDN);
+  if (! (mpfr_zero_p (y) && MPFR_IS_POS (y)))
+    {
+      printf ("Error: eint(-Inf) != +0\n");
+      exit (1);
+    }
+
   /* eint(+/-0) = -Inf */
   mpfr_set_ui (x, 0, MPFR_RNDN);
   mpfr_eint (y, x, MPFR_RNDN);