commit 1896793520a49a6f97ae360c0b288967e56b005e
author pdox <pdox@alum.mit.edu> Wed Oct 25 23:03:01 2017 -0700
committer Benjamin Peterson <benjamin@python.org> Wed Oct 25 23:03:01 2017 -0700
tree b757b6b4691e52d5f3d22177ac23de50ad7d1d25
parent 32318930da70ff03320ec50813b843e7db6fbc2e

bpo-31857: Make the behavior of USE_STACKCHECK deterministic (#4098)

Python/ceval.c

diff --git a/Python/ceval.c b/Python/ceval.c
index 58a2513..f6519cf 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -469,13 +469,15 @@
     int recursion_limit = _PyRuntime.ceval.recursion_limit;
 
 #ifdef USE_STACKCHECK
+    tstate->stackcheck_counter = 0;
     if (PyOS_CheckStack()) {
         --tstate->recursion_depth;
         PyErr_SetString(PyExc_MemoryError, "Stack overflow");
         return -1;
     }
-#endif
+    /* Needed for ABI backwards-compatibility (see bpo-31857) */
     _Py_CheckRecursionLimit = recursion_limit;
+#endif
     if (tstate->recursion_critical)
         /* Somebody asked that we don't check for recursion. */
         return 0;

Python/pystate.c

diff --git a/Python/pystate.c b/Python/pystate.c
index d85d604..82ebf4d 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -245,6 +245,7 @@
         tstate->recursion_depth = 0;
         tstate->overflowed = 0;
         tstate->recursion_critical = 0;
+        tstate->stackcheck_counter = 0;
         tstate->tracing = 0;
         tstate->use_tracing = 0;
         tstate->gilstate_counter = 0;