Address code review

Author: corona10

Include/internal/pycore_typeobject.h

@@ -269,9 +269,14 @@ extern unsigned int _PyType_GetVersionForCurrentState(PyTypeObject *tp);
 PyAPI_FUNC(void) _PyType_SetVersion(PyTypeObject *tp, unsigned int version);
 PyTypeObject *_PyType_LookupByVersion(unsigned int version);
 
-// Returns 0 on success or caller-specific error on failure.
+// Function pointer type for user-defined validation function that will be
+// called by _PyType_Validate().
+// It should return 0 if the validation is passed, otherwise it will return -1.
 typedef int (*_py_validate_type)(PyTypeObject *);
-// Returns 0 on success, -1 if no type version could be assigned, or the error returned by validate
+
+// It will verify the ``ty`` through user-defined validation function ``validate``,
+// and if the validation is passed, it will set the ``tp_version`` to the next
+// available version and return 0. Otherwise, it will return an error code.
 extern int _PyType_Validate(PyTypeObject *ty, _py_validate_type validate, unsigned int *tp_version);
 
 #ifdef __cplusplus

Python/specialize.c

@@ -2749,10 +2749,6 @@ _Py_Specialize_ToBool(_PyStackRef value_o, _Py_CODEUNIT *instr)
         }
 
         assert(err == 0);
-        if (version == 0) {
-            unspecialize(instr, SPEC_FAIL_OUT_OF_VERSIONS);
-            return;
-        }
         assert(version);
         write_u32(cache->version, version);
         specialize(instr, TO_BOOL_ALWAYS_TRUE);