Bug #742342: make Python stop segfaulting on infinitely-recursive reload()s. Fixed by patch #922167.
Will backport.
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 3a9e75e..3e5ecfe 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -194,6 +194,9 @@
 	interp->modules = PyDict_New();
 	if (interp->modules == NULL)
 		Py_FatalError("Py_Initialize: can't make modules dictionary");
+	interp->modules_reloading = PyDict_New();
+	if (interp->modules_reloading == NULL)
+		Py_FatalError("Py_Initialize: can't make modules_reloading dictionary");
 
 #ifdef Py_USING_UNICODE
 	/* Init Unicode implementation; relies on the codec registry */
@@ -531,6 +534,7 @@
 	/* XXX The following is lax in error checking */
 
 	interp->modules = PyDict_New();
+	interp->modules_reloading = PyDict_New();
 
 	bimod = _PyImport_FindExtension("__builtin__", "__builtin__");
 	if (bimod != NULL) {