From 601d3b02df7f664051feba0340c3618cf8474acd Mon Sep 17 00:00:00 2001
From: Kagami Hiiragi <kagami@genshiken.org>
Date: Wed, 22 Jan 2020 16:33:41 +0100
Subject: [PATCH] Import PyIOBase_Type at module time

Fixes #74 and https://bugzilla.redhat.com/show_bug.cgi?id=1792949#c3.
---
 pygraphviz/graphviz.i | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/pygraphviz/graphviz.i b/pygraphviz/graphviz.i
index 68265ce..7cd674f 100644
--- a/pygraphviz/graphviz.i
+++ b/pygraphviz/graphviz.i
@@ -13,14 +13,33 @@
 
 %{
 #if PY_VERSION_HEX >= 0x03000000
-extern PyTypeObject PyIOBase_Type;
+static PyObject *PyIOBase_TypeObj;
+
+static int init_file_emulator(void)
+{
+    PyObject *io = PyImport_ImportModule("_io");
+    if (io == NULL)
+        return -1;
+    PyIOBase_TypeObj = PyObject_GetAttrString(io, "_IOBase");
+    if (PyIOBase_TypeObj == NULL)
+        return -1;
+    return 0;
+}
+#endif
+%}
+
+%init %{
+#if PY_VERSION_HEX >= 0x03000000
+if (init_file_emulator() < 0) {
+    return NULL;
+}
 #endif
 %}
 
 %typemap(in) FILE* (int fd, PyObject *mode_obj, PyObject *mode_byte_obj, char *mode) {
 %#if PY_VERSION_HEX >= 0x03000000 || defined(PYPY_VERSION)
 %#if !defined(PYPY_VERSION)
-    if (!PyObject_IsInstance($input, (PyObject *)&PyIOBase_Type)) {
+    if (!PyObject_IsInstance($input, PyIOBase_TypeObj)) {
         PyErr_SetString(PyExc_TypeError, "not a file handle");
         return NULL;
     }