add assert

Author: iritkatriel

Python/ceval.c

@@ -718,6 +718,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
         /* Because this avoids the RESUME,
          * we need to update instrumentation */
         _Py_Instrument(_PyFrame_GetCode(frame), tstate->interp);
+        assert (frame->instr_ptr == frame->prev_instr + 1);
         monitor_throw(tstate, frame, frame->prev_instr);
         /* TO DO -- Monitor throw entry. */
         goto resume_with_error;
@@ -733,7 +734,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
 #define SET_LOCALS_FROM_FRAME() \
     /* Jump back to the last instruction executed... */ \
     assert (frame->instr_ptr == frame->prev_instr + 1); \
-    next_instr = frame->prev_instr + 1; \
+    next_instr = frame->instr_ptr; \
     stack_pointer = _PyFrame_GetStackPointer(frame);
 
 start_frame: