bpo-33612: Remove PyThreadState_Clear() assertion (GH-7069) (GH-7074)

bpo-25612, bpo-33612: Remove an assertion from PyThreadState_Clear()
which failed at Python shutdown or on fork if a thread was running a
generator.
(cherry picked from commit b6dccf54fd3bac9c87348d96f9d6b571608c15bc)

Co-authored-by: Victor Stinner <vstinner@redhat.com>

diff --git a/Python/pystate.c b/Python/pystate.c
index 7750f4ca8a55a8e85c13d4f311b272e2a6239374..15761e7da90f8e38afcdfe9c89863be0a46fc2ca 100644 (file)
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -581,7 +581,6 @@ PyThreadState_Clear(PyThreadState *tstate)
     Py_CLEAR(tstate->exc_state.exc_traceback);
 
     /* The stack of exception states should contain just this thread. */
-    assert(tstate->exc_info->previous_item == NULL);
     if (Py_VerboseFlag && tstate->exc_info != &tstate->exc_state) {
         fprintf(stderr,
           "PyThreadState_Clear: warning: thread still has a generator\n");