Markdown compat

[mjschultz]

The current apply_markdown generates the following DeprecationWarnings:

markdown/__init__.py:143: DeprecationWarning: "safe_mode" is deprecated in Python-Markdown. Use an HTML sanitizer (like Bleach http://bleach.readthedocs.org/) if you are parsing untrusted markdown text. See the 2.6 release notes for more info

markdown/__init__.py:222: DeprecationWarning: Setting configs in the Named Extension string is deprecated. It is recommended that you pass an instance of the extension class to Markdown or use the "extension_configs" keyword. The current behavior will raise an error in version 2.7. See the Release Notes for Python-Markdown version 2.6 for more info.

markdown/__init__.py:259: DeprecationWarning: Using short names for Markdown's builtin extensions is deprecated. Use the full path to the extension with Python's dot notation (eg: "markdown.extensions.headerid" instead of "headerid"). The current behavior will raise an error in version 2.7. See the Release Notes for Python-Markdown version 2.6 for more info.

These three commits correct them per the Python-Markdown 2.6 release notes.

[jpadilla]

@mjschultz looks good to me, thanks!

[tomchristie]

Great. Which versions does this now work against? Do we need to double check that against what we current list as supported?

[mjschultz]

It looks like extension_configs was introduced in python-markdown 2.5 which has been out for a year. I'm not sure what version(s) of markdown you'd like to support down to though?

Is there a way to automate this or should I manually verify markdown versions from current down to something?

[mjschultz]

Here is what I have right now running ./runtests.py --fast:

env	py2.7	py3.4
markdown==2.6.4	x	x
markdown==2.5.2	x	x
markdown==2.4.1	x	x
markdown==2.3.1	x	x
markdown==2.2.1	x	x
markdown==2.1.1	x	x
markdown==2.0.3

[tomchristie]

Okay. Currently the homepage lists 2.1.0+ as our requirement.
We could either:

• Bump to 2.2 (Not ideal since it'd be in a minor release)
• Ensure that the compat handles both styles dep on what's available.
• Something else?

[mjschultz]

Okay, it turns out in markdown 2.2 they changed the extensions framework a bit to permit external modules with more ease. This means that 2.1 would force a markdown.extensions in front of the headerid causing the errors.

I added some changes that check markdown.version and set the headerid extension path based on that. I updated the checklist above.

I also bumped the markdown version in requirements-optionals.txt.

[xordoquy]

Closed in favor of #3842.
Thanks @mjschultz and sorry this didn't got merged faster.