Mercurial > cpython-lru_cache-weakref
diff Objects/stringobject.c @ 33019:5218bff56449 legacy-trunk
Subclasses of string can no longer be interned. The semantics of
interning were not clear here -- a subclass could be mutable, for
example -- and had bugs. Explicitly interning a subclass of string
via intern() will raise a TypeError. Internal operations that attempt
to intern a string subclass will have no effect.
Added a few tests to test_builtin that includes the old buggy code and
verifies that calls like PyObject_SetAttr() don't fail. Perhaps these
tests should have gone in test_string.
| author | Jeremy Hylton <jeremy@alum.mit.edu> |
|---|---|
| date | Sat, 07 Aug 2004 19:20:05 +0000 |
| parents | 3706a3704aea |
| children | 4f588f57a93b |
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--- a/Objects/stringobject.c Sat Aug 07 19:16:32 2004 +0000 +++ b/Objects/stringobject.c Sat Aug 07 19:20:05 2004 +0000 @@ -4313,6 +4313,10 @@ PyObject *t; if (s == NULL || !PyString_Check(s)) Py_FatalError("PyString_InternInPlace: strings only please!"); + /* If it's a string subclass, we don't really know what putting + it in the interned dict might do. */ + if (!PyString_CheckExact(s)) + return; if (PyString_CHECK_INTERNED(s)) return; if (interned == NULL) { @@ -4322,36 +4326,22 @@ return; } } - if ((t = PyDict_GetItem(interned, (PyObject *)s)) != NULL) { + t = PyDict_GetItem(interned, (PyObject *)s); + if (t) { Py_INCREF(t); Py_DECREF(*p); *p = t; return; } - /* Ensure that only true string objects appear in the intern dict */ - if (!PyString_CheckExact(s)) { - t = PyString_FromStringAndSize(PyString_AS_STRING(s), - PyString_GET_SIZE(s)); - if (t == NULL) { - PyErr_Clear(); - return; - } - } else { - t = (PyObject*) s; - Py_INCREF(t); - } - - if (PyDict_SetItem(interned, t, t) == 0) { - /* The two references in interned are not counted by - refcnt. The string deallocator will take care of this */ - ((PyObject *)t)->ob_refcnt-=2; - PyString_CHECK_INTERNED(t) = SSTATE_INTERNED_MORTAL; - Py_DECREF(*p); - *p = t; + + if (PyDict_SetItem(interned, s, s) < 0) { + PyErr_Clear(); return; } - Py_DECREF(t); - PyErr_Clear(); + /* The two references in interned are not counted by refcnt. + The string deallocator will take care of this */ + (*p)->ob_refcnt -= 2; + PyString_CHECK_INTERNED(s) = SSTATE_INTERNED_MORTAL; } void