From ba7134c2a29e96ca79edf2e8ab6bb6367c72abab Mon Sep 17 00:00:00 2001
From: Richard Harrison <rjh@zaretto.com>
Date: Sun, 29 Dec 2019 13:50:21 +0100
Subject: [PATCH] Use isfinite to determine if an FP number is valid.

ref: https://forum.flightgear.org/viewtopic.php?f=30&t=36600&sid=4bdfcb69abb4a6440cd8965aa03815d5#p357164
---
 simgear/nasal/mathlib.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/simgear/nasal/mathlib.c b/simgear/nasal/mathlib.c
index 7c8210f0..78fd1a26 100644
--- a/simgear/nasal/mathlib.c
+++ b/simgear/nasal/mathlib.c
@@ -9,9 +9,7 @@
 
 static int valid(double d)
 {
-    union { double d; unsigned long long ull; } u;
-    u.d = d;
-    return ((u.ull >> 52) & 0x7ff) != 0x7ff;
+    return isfinite(d);
 }
 
 static naRef die(naContext c, const char* fn)