misc/openvdb: Replace the dependency on python 2.7 with the default python (currently 3.x)

PR:		244347
Submitted by:	VVD <vvd@unislabs.com>

misc/openvdb/Makefile

@@ -28,7 +28,7 @@ OPTIONS_DEFINE=		PYTHON TOOLS DOCS # TOOLS should be a subpackage
 OPTIONS_DEFAULT=	PYTHON TOOLS
 OPTIONS_SUB=		yes
 
-PYTHON_USES=		python:2.7 # 3.6 is broken: https://github.com/AcademySoftwareFoundation/openvdb/issues/427
+PYTHON_USES=		python
 PYTHON_CMAKE_BOOL=	OPENVDB_BUILD_PYTHON_MODULE
 PYTHON_CMAKE_ON=	-DFREEBSD_PYTHON_VER:STRING=${PYTHON_VER} -DUSE_NUMPY:BOOL=ON
 PYTHON_LIB_DEPENDS=	${PY_BOOST}

misc/openvdb/files/patch-openvdb_python_pyOpenVDBModule.cc

@@ -0,0 +1,26 @@
+--- openvdb/python/pyOpenVDBModule.cc.orig	2019-05-07 20:58:35 UTC
++++ openvdb/python/pyOpenVDBModule.cc
+@@ -320,7 +320,11 @@ struct PointIndexConverter
+     /// @return nullptr if the given Python object is not convertible to the PointIndex.
+     static void* convertible(PyObject* obj)
+     {
++#if PY_MAJOR_VERSION >= 3
++	if (!PyLong_Check(obj)) return nullptr; // not a Python integer
++#else
+         if (!PyInt_Check(obj)) return nullptr; // not a Python integer
++#endif
+         return obj;
+     }
+ 
+@@ -337,7 +341,11 @@ struct PointIndexConverter
+         // Extract the PointIndex from the python integer
+         PointIndexT* index = static_cast<PointIndexT*>(storage);
+ 
++#if PY_MAJOR_VERSION >= 3
++	*index = static_cast<IntType>(PyLong_AsLong(obj));
++#else
+         *index = static_cast<IntType>(PyInt_AsLong(obj));
++#endif
+     }
+ 
+     /// Register both the PointIndex-to-integer and the integer-to-PointIndex converters.