email.utils.decode_params not supporting params that contain hyphens

Bug report

Bug description:

The decode_params function from email.utils is failing to combine the parameters from multiple lines if the name of the parameter includes a hyphen "-". Maybe it's this regex which is too strict: https://github.com/python/cpython/blob/9d1e668e6f40967dda5cbb1ce298bf0dff2d807c/Lib/email/utils.py#L392-L393

The decode_params function always ignores the first 2-tuple but the first parameter in a SMTP header can already be a multiline parameter. I don't see a reason why the first array element is skipped here:
https://github.com/python/cpython/blob/9d1e668e6f40967dda5cbb1ce298bf0dff2d807c/Lib/email/utils.py#L398-L405

my code to reproduce:

from email.utils import decode_params

decode_params([('parameter-name*0*',"utf-8''start;"),("parameter-name*1*","-middle-;"),("parameter-name*2*","end;")])
# parameter-name is not combined:
#  [('parameter-name*0*', "utf-8''start;"), ('parameter-name*1*', '"-middle-;"'), ('parameter-name*2*', '"end;"')]

decode_params([('parametername*0*',"utf-8''start;"),("parametername*1*","-middle-;"),("parametername*2*","end;")])
# parametername is combined but not the first 2-tuple:
# [('parametername*0*', "utf-8''start;"), ('parametername', (None, None, '"-middle-;end;"'))]

decode_params([("ignored","ignored"),('parametername*0*',"utf-8''start;"),("parametername*1*","-middle-;"),("parametername*2*","end;")])
# parametername is now combined as expected, the additional entry can be ignored when processing the output
# [('ignored', 'ignored'), ('parametername', ('utf-8', '', '"start;-middle-;end;"'))]

Thank you
Michael

CPython versions tested on:

3.12

Operating systems tested on:

Linux

Linked PRs

• gh-153536

从 Lib/email/utils.py 中的 decode_params 开始，检查所引用正则表达式附近的参数名称解析，以及初始元组的处理。重现 issue 中的三个示例，然后将行为与链接的 PR gh-153536 进行比较。完成的标准是：带连字符的参数名称和第一个多行参数能够得到一致处理，同时不会使现有情况发生回归。