ShareableList removes trailing zeroes from strings and bytes

Bug report

from multiprocessing.shared_memory import ShareableList
s, b = '\x00\x01\x00', bytes([0,1,0])
sl = ShareableList([s, b])
s == sl[0], b == sl[1]

gives (False, False) because the trailing zeroes get lost in the ShareableList: sl holds ShareableList(['\x00\x01', b'\x00\x01'], name='wnsm_...'). I would expect that strings and bytes keep the trailing zeroes also when added to a ShareableList.

Your environment

• CPython versions tested on: 3.8.5, 3.10.6
• Operating system and architecture: Windows 10, 64bit

Analysis

There are three places in class ShareableList in Lib/multiprocessing/shared_memory.py, where trailing zeroes are explicitely removed: ...rstrip(b'\x00').... For what reason?

从 Lib/multiprocessing/shared_memory.py 开始，检查使用 rstrip(b'\x00') 的三个 ShareableList 位置；复现所提供的示例以确认该行为。完成的标准是字符串和 bytes 保留末尾的零，同时现有的 ShareableList 行为保持不变，并在项目中该入口点对应的测试所在位置添加回归覆盖。