From 3fae8e0ba9090991b0ac9a69b714df7544a9c707 Mon Sep 17 00:00:00 2001
From: h_vogt <h_vogt>
Date: Wed, 9 Oct 2013 21:39:50 +0200
Subject: [PATCH] xpressn.c: add domain check for acosh, atanh replacement
 functions

---
 src/frontend/numparam/xpressn.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/frontend/numparam/xpressn.c b/src/frontend/numparam/xpressn.c
index 6aed9d4e0..2bd039d28 100644
--- a/src/frontend/numparam/xpressn.c
+++ b/src/frontend/numparam/xpressn.c
@@ -194,14 +194,22 @@ mathfunction(int f, double z, double x)
 #ifdef HAVE_ACOSH
         y = acosh(x);
 #else
-        y = (log(x + sqrt(x*x-1.0)));
+        /* domain check (HUGE_VAL like gnu libc) */
+        if (x < 1.)
+            y = HUGE_VAL;
+        else
+            y = (log(x + sqrt(x*x-1.0)));
 #endif
         break;
     case 33:
 #ifdef HAVE_ATANH
         y = atanh(x);
 #else
-        y = (log((1.0 + x) / (1.0 - x)) / 2.0);
+        /* domain check (HUGE_VAL like gnu libc) */
+        if (fabs(x) >= 1.)
+            y = HUGE_VAL;
+        else
+            y = (log((1.0 + x) / (1.0 - x)) / 2.0);
 #endif
         break;
     case 34: