$OpenBSD: patch-src_analysis_interpolation_qgsinterpolator_cpp,v 1.1 2009/10/29 19:59:38 landry Exp $
--- src/analysis/interpolation/qgsinterpolator.cpp.orig	Tue Oct 27 20:45:47 2009
+++ src/analysis/interpolation/qgsinterpolator.cpp	Tue Oct 27 20:46:01 2009
@@ -92,7 +92,7 @@ int QgsInterpolator::cacheBaseData()
           continue;
         }
         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
         {
           continue;
         }
