+ fix bug in mesh bounding box, fix clang warning

src/App/PropertyStandard.cpp

@@ -283,7 +283,7 @@ void PropertyEnumeration::setEnums(const char** plEnums)
         // check for NULL termination
         const char* p = *_EnumArray;
         unsigned int i=0;
-        while(*(p++) != NULL)i++;
+        while(*(p++) != 0)i++;
             // very unlikely to have enums with more then 5000 entries!
             assert(i<5000);
     }

src/Mod/Mesh/App/Mesh.cpp

@@ -148,11 +148,13 @@ Base::BoundBox3d MeshObject::getBoundBox(void)const
 {
     const_cast<MeshCore::MeshKernel&>(_kernel).RecalcBoundBox();
     Base::BoundBox3f Bnd = _kernel.GetBoundBox();
-    
+
     Base::BoundBox3d Bnd2;
-    for(int i =0 ;i<=7;i++)
-        Bnd2.Add(transformToOutside(Bnd.CalcPoint(i)));
-    
+    if (Bnd.IsValid()) {
+        for (int i =0 ;i<=7;i++)
+            Bnd2.Add(transformToOutside(Bnd.CalcPoint(i)));
+    }
+
     return Bnd2;
 }