bpo-20526: Fix PyThreadState_Clear(): don't decref frame (GH-19120) (GH-19136)
PyThreadState.frame is a borrowed reference, not a strong reference:
PyThreadState_Clear() must not call Py_CLEAR(tstate->frame).
Remove test_threading.test_warnings_at_exit(): we cannot warranty
that the Python thread state of daemon threads is cleared in a
reliable way during Python shutdown.
(cherry picked from commit 5804f878e779712e803be927ca8a6df389d82cdf)
diff --git a/Include/cpython/pystate.h b/Include/cpython/pystate.h
index 94b0809..e22b053 100644
--- a/Include/cpython/pystate.h
+++ b/Include/cpython/pystate.h
@@ -55,6 +55,7 @@
struct _ts *next;
PyInterpreterState *interp;
+ /* Borrowed reference to the current frame (it can be NULL) */
struct _frame *frame;
int recursion_depth;
char overflowed; /* The stack has overflowed. Allow 50 more calls