Fix rrdtool.graph python binding

It was failing with 'munmap_chunk(): invalid pointer' error in python 3.6.3

diff --git a/bindings/python/rrdtoolmodule.c b/bindings/python/rrdtoolmodule.c
index eeefb581e9d481a99017e84a978ff9650a149fc9..9a11945d0264b5cb12fef7371d99e413c018af0c 100644 (file)
--- a/bindings/python/rrdtoolmodule.c
+++ b/bindings/python/rrdtoolmodule.c
@@ -595,7 +595,7 @@ _rrdtool_graph(PyObject *Py_UNUSED(self), PyObject *args)
     PyObject *ret;
     int xsize, ysize, i, status;
     double ymin, ymax;
-    char **calcpr;
+    char **calcpr = NULL;
 
     if (convert_args("graph", args, &rrdtool_argv, &rrdtool_argc) == -1)
         return NULL;