#4236: avoid possible Fatal Error when import is called from __del__

Patch by Simon Cross, crasher test code by Martin von Löwis.

Lib/test/test_import.py

@@ -9,11 +9,13 @@ import random
 import stat
 import sys
 import unittest
+import textwrap
 
 from test.support import (
     EnvironmentVarGuard, TESTFN, check_warnings, forget, is_jython,
     make_legacy_pyc, rmtree, run_unittest, swap_attr, swap_item, temp_umask,
     unlink, unload)
+from test import script_helper
 
 
 def remove_files(name):
@@ -284,6 +286,17 @@ class ImportTests(unittest.TestCase):
         self.assertEqual("Import by filename is not supported.",
                          c.exception.args[0])
 
+    def test_import_in_del_does_not_crash(self):
+        # Issue 4236
+        testfn = script_helper.make_script('', TESTFN, textwrap.dedent("""\
+            import sys
+            class C:
+               def __del__(self):
+                  import imp
+            sys.argv.insert(0, C())
+            """))
+        script_helper.assert_python_ok(testfn)
+
 
 class PycRewritingTests(unittest.TestCase):
     # Test that the `co_filename` attribute on code objects always points

Misc/NEWS

@@ -7,6 +7,12 @@ What's New in Python 3.2 Beta 2?
 
 *Release date: XXXX-XX-XX*
 
+Core and Builtins
+-----------------
+
+- Issue #4236: PyModule_Create2 now checks the import machinery directly
+  rather than the Py_IsInitialized flag, avoiding a Fatal Python
+  error in certain circumstances when an import is done in __del__.
 
 Library
 -------

Objects/moduleobject.c

@@ -63,8 +63,9 @@ PyModule_Create2(struct PyModuleDef* module, int module_api_version)
     PyMethodDef *ml;
     const char* name;
     PyModuleObject *m;
-    if (!Py_IsInitialized())
-        Py_FatalError("Interpreter not initialized (version mismatch?)");
+    PyInterpreterState *interp = PyThreadState_Get()->interp;
+    if (interp->modules == NULL)
+        Py_FatalError("Python import machinery not initialized");
     if (PyType_Ready(&moduledef_type) < 0)
         return NULL;
     if (module->m_base.m_index == 0) {