EmailMessage.get_filename() not unquoting url encodings

Bug report

Bug description:

import requests
from email.message import EmailMessage

def get_filename_from_url(url, url_response=None):
    if url_response == None:
        url_response = requests.get(url)
        url_response.raise_for_status()
    
    content_disposition = url_response.headers.get("Content-Disposition")
    if content_disposition:
        email_message = EmailMessage()
        email_message["Content-Disposition"] = content_disposition
        return email_message.get_filename()


url = "https://www.gsi.gov.in/webcenter/ShowProperty;jsessionid=yv2xehEKwHR0ZHf64V2sMbrFzRSeSGCvcxDVr9F4_rbXBVtcgKbl!1598077039!1556223610?nodeId=%2FUCM%2FDCPORT1GSIGOVI063041%2F%2FidcPrimaryFile&revision=latestreleased"
get_filename_from_url(url)

output

annoncement_of%20computer%20application%20_rti_er%20_16122014.pdf

if i use

from urllib.parse import unquote
unquote(email_message.get_filename())

i am getting unquoted output

annoncement_of computer application _rti_er _16122014.pdf

why a different unquote function is used in EmailMessage.get_filename() ?

CPython versions tested on:

CPython main branch

Operating systems tested on:

Windows

从 EmailMessage.get_filename() 入口点开始，使用提供的 URL 和标头值重现报告的 Content-Disposition 行为。将其解码行为与 urllib.parse.unquote 进行比较，然后确定预期的文件名处理方式；如果 issue 确认存在 bug，则添加或更新回归覆盖。