From b6855683cc808054349af9945653f6c626c3c8da Mon Sep 17 00:00:00 2001
From: Brett Cannon <brett@python.org>
Date: Fri, 3 Feb 2012 12:08:03 -0500
Subject: [PATCH] Check for errors in creating sub-interpreters when testing
 the C API.

---
 Modules/_testcapimodule.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index b00ac20b8e1..bcb3a0fcbf2 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -2396,6 +2396,14 @@ run_in_subinterp(PyObject *self, PyObject *args)
     PyThreadState_Swap(NULL);
 
     substate = Py_NewInterpreter();
+    if (substate == NULL) {
+        /* Since no new thread state was created, there is no exception to
+           propagate; raise a fresh one after swapping in the old thread
+           state. */
+        PyThreadState_Swap(mainstate);
+        PyErr_SetString(PyExc_RuntimeError, "sub-interpreter creation failed");
+        return NULL;
+    }
     r = PyRun_SimpleString(code);
     Py_EndInterpreter(substate);