$OpenBSD: patch-src_analysis_interpolation_qgstininterpolator_cpp,v 1.2 2010/01/11 20:13:31 landry Exp $
--- src/analysis/interpolation/qgstininterpolator.cpp.orig	Sun Nov 22 15:41:00 2009
+++ src/analysis/interpolation/qgstininterpolator.cpp	Mon Jan 11 16:39:31 2010
@@ -195,7 +195,7 @@ int QgsTINInterpolator::insertData( QgsFeature* f, boo
       return 3;
     }
     attributeValue = att_it.value().toDouble( &attributeConversionOk );
-    if ( !attributeConversionOk || isnan( attributeValue ) ) //don't consider vertices with attributes like 'nan' for the interpolation
+    if ( !attributeConversionOk || __gnu_cxx::isnan( attributeValue ) ) //don't consider vertices with attributes like 'nan' for the interpolation
     {
       return 4;
     }
