Iterating over ctypes pointer causes hang or segmentation fault

Trying to create iterable (list, tuple, set etc.) from PyCPointer instance leads to hang or segmentation fault.
This code causes hang and memory leak which goes until oom-killer kills python process:

import ctypes
x = ctypes.c_int32(12345)
buf4_p_t = ctypes.POINTER(ctypes.ARRAY(ctypes.c_byte, 4))
buf_p = ctypes.cast(ctypes.byref(x), buf4_p_t)
list(buf_p)

Similar code that causes segmentation fault:

import ctypes
x = ctypes.c_int32(54321)
xp = ctypes.pointer(x)
list(xp)

Iterating over pointer using for statement leads to an infinite loop:
for i in buf_p: print(i)
for i in xp: print(i)
list(for i in buf_p)

Tried on 3.10.3 and 3.11.0a6+, fails at both.

The possible reason is that PyCPointer_Type defines sq_item without defining tp_iter.
Despite I can't imagine any reason why anyone might need to use pointer as iterable/sequence, raising TypeError in such situation would be a better option.

Linked PRs

• gh-126318
• gh-157801

Commencez par le comportement de ctypes PyCPointer montré dans les deux reproductions et confirmez le blocage, la croissance de la mémoire et la faute de segmentation dans les versions de Python concernées. Suivez l’interaction entre l’indexation des pointeurs et l’itération, puis vérifiez que le comportement final rejette l’itération de manière sûre, sans se bloquer ni provoquer de plantage ; les PRs liées gh-126318 et gh-157801 fournissent un travail existant à examiner.