Refleak demo

Author: Fidget-Spinner

Include/internal/pycore_opcode_metadata.h

@@ -55,7 +55,7 @@ typedef struct {
 #include "pycore_context.h"       // _PyContextTokenMissing
 
 // Define this to get precise tracking of stackrefs.
-// #define Py_STACKREF_DEBUG 1
+#define Py_STACKREF_DEBUG 1
 
 typedef union _PyStackRef {
 #if !defined(Py_GIL_DISABLED) && defined(Py_STACKREF_DEBUG)

Include/internal/pycore_structs.h

@@ -909,7 +909,10 @@ dummy_func(
             PyObject *res_o = (PyObject*)&_Py_SINGLETON(strings).ascii[c];
             PyStackRef_CLOSE_SPECIALIZED(sub_st, _PyLong_ExactDealloc);
             DEAD(sub_st);
-            PyStackRef_CLOSE(str_st);
+            // Let's say I forgot to close this
+            // PyStackRef_CLOSE(str_st);
+            // ... Instead I mark it dead
+            DEAD(str_st);
             res = PyStackRef_FromPyObjectImmortal(res_o);
         }