* math.c (math_atanh): raise ERANGE without calling atanh if absolute

  value is 1 to achieve platform-independent math.  [ruby-core:28219]

* math.c (math_lgamma): return [Infinity, 1] without calling lgamma_r
  if argument is infinity or -infinity.  [ruby-core:28219]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@26707 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 7 insertions, 0 deletions

diff --git a/math.c b/math.c
index 027932dee9..51a89c3f55 100644
--- a/math.c
+++ b/math.c
@@ -310,6 +310,10 @@ math_atanh(VALUE obj, VALUE x)
     Need_Float(x);
     errno = 0;
     d0 = RFLOAT_VALUE(x);
+    if (d0 == 1.0 || d0 == -1.0) {
+	errno = ERANGE;
+	rb_sys_fail("atanh");
+    }
     d = atanh(d0);
     domain_check(d0, d, "atanh");
     infinity_check(x, d, "atanh");
@@ -715,6 +719,9 @@ math_lgamma(VALUE obj, VALUE x)
     Need_Float(x);
     errno = 0;
     d0 = RFLOAT_VALUE(x);
+    if (isinf(d0)) {
+	return rb_assoc_new(DBL2NUM(INFINITY), INT2FIX(1));
+    }
     d = lgamma_r(d0, &sign);
     domain_check(d0, d, "lgamma");
     v = DBL2NUM(d);