From: Martin Taibr <taibr.martin@gmail.com>
Date: Sun, 29 Sep 2019 10:26:43 +0000 (+0200)
Subject: fix isnan
X-Git-Tag: xonotic-v0.8.5~1255
X-Git-Url: https://git.rm.cloudns.org/?a=commitdiff_plain;h=16225fa152cd4b9bd9d663b9538989bd3f789999;p=xonotic%2Fxonotic-data.pk3dir.git

fix isnan
---

diff --git a/qcsrc/lib/warpzone/mathlib.qc b/qcsrc/lib/warpzone/mathlib.qc
index 9105269ff..cf86d97f9 100644
--- a/qcsrc/lib/warpzone/mathlib.qc
+++ b/qcsrc/lib/warpzone/mathlib.qc
@@ -27,10 +27,13 @@ bool isnan(float e)
 	// the sane way to detect NaN is broken because of a compiler bug
 	// (works with constants but breaks when assigned to variables)
 	// use conversion to string instead
-
 	//float f = e;
 	//return (e != f);
-	return ftos(e) == "-nan";
+
+	// Negative NaN ("-nan") is much more common but plain "nan" can be created by negating *some* -nans so we need to check both.
+	// DP's QCVM and GMQCC's QCVM behave differently - one needs ftos(-(0.0 / 0.0)), the other ftos(-sqrt(-1)).
+	string s = ftos(e);
+	return s == "nan" || s == "-nan";
 }
 bool isnormal(float e)
 {