\! is being bleached to ?33? for a reason I can't understand.

[Asday]

Python 3.6.5 (default, Mar 29 2018, 03:28:50) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import markdown
>>> from mdx_bleach.extension import BleachExtension
>>> bleach = BleachExtension()
>>> md = markdown.Markdown(extensions=[bleach])
>>> md.convert('\\!')
'<p>?33?</p>'
>>> md_no_bleach = markdown.Markdown()
>>> md_no_bleach.convert('\\!')
'<p>!</p>'
>>> import bleach
>>> bleach.clean('\\!')
'\\!'
>>> bleach.__version__
'2.1.3'
>>> markdown.__version__.version
'2.6.11'
>>> import mdx_bleach
>>> mdx_bleach.VERSION
'0.1.2'
>>> 

As demonstrated, the issue only occurs when using this extension, but looking over the code I can't figure out why.

[Wenzil]

After some testing I found this was caused by a breaking change in Bleach 2.0.

I published a new release that freezes the bleach dependency to versions below 2.0 and it seems to have fixed it. Try reinstalling mdx_bleach and let me know if it works

[Asday]

Thank you.

I trust you that it does, but I would argue that that's not the best solution. Bleach being a security library; forcing users to be on an old version seems bad.

[Wenzil]

Good point, I'll revert the change I made.

Here's a link to the downstream breaking change. It's not documenting very well the reason behind it though. I suggest asking them about it.

https://bleach.readthedocs.io/en/latest/changes.html#version-2-0-march-8th-2017

bleach.clean and friends were rewritten

clean was reimplemented as an html5lib filter and happens at a different step in the HTML parsing -> traversing -> serializing process. Because of that, there are some differences in clean’s output as compared with previous versions.