[goffice] Math: generate positive nan.

[Morten Welinder <mortenw src gnome org>]

commit 77f1349fae8f762fbca9e8cec80f7e6875a96dff
Author: Morten Welinder <terra gnome org>
Date:   Fri Mar 20 17:49:19 2015 -0400

    Math: generate positive nan.
    
    For some reason doing +inf*+0 gives a negative nan.  Send it through
    fabs.

 ChangeLog              |    4 ++++
 goffice/math/go-math.c |    2 +-
 2 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index e10e154..485fa09 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2015-03-20  Morten Welinder  <terra gnome org>
+
+       * goffice/math/go-math.c (_go_math_init): generate positive nan.
+
 2015-03-19  Jean Brefort  <jean brefort normalesup org>
 
        * goffice/graph/gog-axis-line.c (axis_line_point): fix selection of
diff --git a/goffice/math/go-math.c b/goffice/math/go-math.c
index fdb9a0d..6c5dfc8 100644
--- a/goffice/math/go-math.c
+++ b/goffice/math/go-math.c
@@ -129,7 +129,7 @@ _go_math_init (void)
 #error "Please do not compile this code with -ffast-math.  It will not work."
 #endif
 
-       go_nan = go_pinf * 0.0;
+       go_nan = fabs (go_pinf * 0.0);
        if (isnan (go_nan))
                goto have_nan;