xmlrpc.client.loads raises IndexError on a malformed struct

Bug description

xmlrpc.client.loads() raises a raw IndexError instead of xmlrpc.client.ResponseError when unmarshalling a <struct> that contains a <member> with a <name> but no <value>.

Unmarshaller.end_struct iterates the stacked items in pairs (items[i], items[i+1]). A <member> missing its <value> leaves an odd number of items, so items[i+1] raises IndexError.

The unmarshaller already raises ResponseError for sibling malformed cases (empty stack at line 640, unknown tag inside <data> at line 663).

Reproducer:

import xmlrpc.client

data = (b'<?xml version="1.0"?>'
        b'<methodResponse><params><param><value>'
        b'<struct><member><name>k</name></member></struct>'
        b'</value></param></params></methodResponse>')

xmlrpc.client.loads(data)
# IndexError: list index out of range

Expected: xmlrpc.client.ResponseError.

CPython versions tested on

3.13, 3.14, 3.15, main

Operating systems tested on

macOS

Linked PRs

• gh-153805

從 Unmarshaller.end_struct 開始，issue 在這裡指出了會引發 IndexError 的成對迭代，並將其與第 640 行和第 663 行附近現有的格式錯誤輸入處理進行比較。當 reproducer 引發 xmlrpc.client.ResponseError 而不是 IndexError 時，即表示完成；關聯的 PR gh-153805 表明這項工作已經在進行中。