[goffice] Introduce go_complex_invalid_p

[Morten Welinder <mortenw src gnome org>]

commit 6bd751eca1384f99bf025453ea278e6f6cd84c4f
Author: Morten Welinder <terra gnome org>
Date:   Mon May 23 19:55:36 2011 -0400

    Introduce go_complex_invalid_p

 goffice/math/go-complex.c |    9 ++++++++-
 goffice/math/go-complex.h |    2 ++
 2 files changed, 10 insertions(+), 1 deletions(-)
---
diff --git a/goffice/math/go-complex.c b/goffice/math/go-complex.c
index 52e10bf..b374d88 100644
--- a/goffice/math/go-complex.c
+++ b/goffice/math/go-complex.c
@@ -311,7 +311,14 @@ int SUFFIX(go_complex_zero_p) (SUFFIX(go_complex) const *src)
 
 /* ------------------------------------------------------------------------- */
 
-DOUBLE  SUFFIX(go_complex_mod) (SUFFIX(go_complex) const *src)
+int SUFFIX(go_complex_invalid_p) (SUFFIX(go_complex) const *src)
+{
+	return !(SUFFIX(go_finite) (src->re) && SUFFIX(go_finite) (src->im));
+}
+
+/* ------------------------------------------------------------------------- */
+
+DOUBLE SUFFIX(go_complex_mod) (SUFFIX(go_complex) const *src)
 {
 	return SUFFIX(hypot) (src->re, src->im);
 }
diff --git a/goffice/math/go-complex.h b/goffice/math/go-complex.h
index 2409913..cf0813e 100644
--- a/goffice/math/go-complex.h
+++ b/goffice/math/go-complex.h
@@ -35,6 +35,7 @@ void go_complex_invalid (go_complex *dst);
 void go_complex_real (go_complex *dst, double re);
 int go_complex_real_p (go_complex const *src);
 int go_complex_zero_p (go_complex const *src);
+int go_complex_invalid_p (go_complex const *src);
 double go_complex_mod (go_complex const *src);
 double go_complex_angle (go_complex const *src);
 double go_complex_angle_pi (go_complex const *src);
@@ -69,6 +70,7 @@ void go_complex_invalidl (go_complexl *dst);
 void go_complex_reall (go_complexl *dst, long double re);
 int go_complex_real_pl (go_complexl const *src);
 int go_complex_zero_pl (go_complexl const *src);
+int go_complex_invalid_pl (go_complexl const *src);
 long double go_complex_modl (go_complexl const *src);
 long double go_complex_anglel (go_complexl const *src);
 long double go_complex_angle_pil (go_complexl const *src);