Add a more general fix for #127 (CPy #20007) based on #136.

[gsnedders]

This gets stuff working with urllib.response.addurlinfo. See #127 and #136.

[hoppipolla-critic-bot]

Critic review: https://critic.hoppipolla.co.uk/r/4800

This is an external review system which you may optionally use for the code review of your pull request.

In order to help critic track your changes, please do not make in-place history rewrites (e.g. via git rebase -i or git commit --amend) when updating this pull request.

[gsnedders]

@SimonSapin this may be of interest to you (maybe)

[SimonSapin]

According to Kozea/WeasyPrint@e14653c , html5lib 0.999 already had a work around that was enough for WeasyPrint. Probably 18bc278.

[SimonSapin]

Oh, looking closer, this is a similar but different work around. I don’t remember WeasyPrint being affected by that one, though.

[gsnedders]

Yeah, from memory you for were just trying to get it to be more complete, rather than needing it yourself. I think?

[SimonSapin]

Maybe. But to be honest I’ve kind of moved on from Python :)

[landscape-bot]

Code quality remained the same when pulling 3b3bc21 on gsnedders:addinfourl-20007 into 082c042 on html5lib:master.

[landscape-bot]

Code quality remained the same when pulling bf7da77 on gsnedders:addinfourl-20007 into 082c042 on html5lib:master.