diff options
Diffstat (limited to 'Modules/datetimemodule.c')
| -rw-r--r-- | Modules/datetimemodule.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/Modules/datetimemodule.c b/Modules/datetimemodule.c index e85c955..164492e 100644 --- a/Modules/datetimemodule.c +++ b/Modules/datetimemodule.c @@ -568,7 +568,18 @@ normalize_datetime(int *year, int *month, int *day, * setting MemoryError. All data members remain uninitialized trash. * * We abuse the tp_alloc "nitems" argument to communicate whether a tzinfo - * member is needed. This is ugly. + * member is needed. This is ugly, imprecise, and possibly insecure. + * tp_basicsize for the time and datetime types is set to the size of the + * struct that has room for the tzinfo member, so subclasses in Python will + * allocate enough space for a tzinfo member whether or not one is actually + * needed. That's the "ugly and imprecise" parts. The "possibly insecure" + * part is that PyType_GenericAlloc() (which subclasses in Python end up + * using) just happens today to effectively ignore the nitems argument + * when tp_itemsize is 0, which it is for these type objects. If that + * changes, perhaps the callers of tp_alloc slots in this file should + * be changed to force a 0 nitems argument unless the type being allocated + * is a base type implemented in this file (so that tp_alloc is time_alloc + * or datetime_alloc below, which know about the nitems abuse). */ static PyObject * |