Index: src/core/qgis.h
===================================================================
--- src/core/qgis.h	(revision 14708)
+++ src/core/qgis.h	(working copy)
@@ -22,11 +22,7 @@
 #include <QString>
 #include <cfloat>
 
-#ifndef Q_OS_MACX
 #include <cmath>
-#else
-#include <math.h>
-#endif
 #ifdef WIN32
 #include <float.h>
 #define isnan(f) _isnan(f)
Index: src/core/qgsclipper.h
===================================================================
--- src/core/qgsclipper.h	(revision 14708)
+++ src/core/qgsclipper.h	(working copy)
@@ -157,10 +157,16 @@
     // look at each edge of the polygon in turn
 
     //ignore segments with nan or inf coordinates
-    if ( isnan( inX[i2] ) || isnan( inY[i2] ) || isinf( inX[i2] ) || isinf( inY[i2] )
-         || isnan( inX[i1] ) || isnan( inY[i1] ) || isinf( inX[i1] ) || isinf( inY[i1] ) )
-    {
-      i1 = i2;
+    #ifndef Q_OS_MACX
+		if ( isnan( inX[i2] ) || isnan( inY[i2] ) || isinf( inX[i2] ) || isinf( inY[i2] )
+    		|| isnan( inX[i1] ) || isnan( inY[i1] ) || isinf( inX[i1] ) || isinf( inY[i1] ) )
+    	{
+	#else
+		if ( std::isnan( inX[i2] ) || std::isnan( inY[i2] ) || std::isinf( inX[i2] ) || std::isinf( inY[i2] )
+	    	|| std::isnan( inX[i1] ) || std::isnan( inY[i1] ) || std::isinf( inX[i1] ) || std::isinf( inY[i1] ) )
+	    {
+    #endif  
+	i1 = i2;
       continue;
     }
 
Index: src/analysis/interpolation/qgsinterpolator.cpp
===================================================================
--- src/analysis/interpolation/qgsinterpolator.cpp	(revision 14708)
+++ src/analysis/interpolation/qgsinterpolator.cpp	(working copy)
@@ -83,9 +83,14 @@
           continue;
         }
         attributeValue = att_it.value().toDouble( &attributeConversionOk );
-        if ( !attributeConversionOk || isnan( attributeValue ) ) //don't consider vertices with attributes like 'nan' for the interpolation
+        #ifndef Q_OS_MACX
+		if ( !attributeConversionOk || isnan( attributeValue ) ) //don't consider vertices with attributes like 'nan' for the interpolation
         {
-          continue;
+	    #else
+		if ( !attributeConversionOk || std::isnan( attributeValue ) ) //don't consider vertices with attributes like 'nan' for the interpolation
+	    {
+        #endif
+  			continue;
         }
       }
 
Index: src/analysis/interpolation/qgstininterpolator.cpp
===================================================================
--- src/analysis/interpolation/qgstininterpolator.cpp	(revision 14708)
+++ src/analysis/interpolation/qgstininterpolator.cpp	(working copy)
@@ -185,8 +185,13 @@
       return 3;
     }
     attributeValue = att_it.value().toDouble( &attributeConversionOk );
+	#ifndef Q_OS_MACX
     if ( !attributeConversionOk || isnan( attributeValue ) ) //don't consider vertices with attributes like 'nan' for the interpolation
     {
+	#else
+    if ( !attributeConversionOk || std::isnan( attributeValue ) ) //don't consider vertices with attributes like 'nan' for the interpolation
+    {
+	#endif
       return 4;
     }
   }