Issues with custom code blocks

[Kwpolska]

Nikola is a static site generator. We’re using a custom code block — it works fine with docutils, but with rst2html5 [(plugin)](, there are indentation issues: getnikola/plugins#152

Unfortunately my patch does not cut it, because that breaks tabs (U+0009).

Here’s a gist with a sample post and differences: https://gist.github.com/Kwpolska/a2d4268a08b60df895180f5aa6fd5513

I have tracked the issue down to a difference in self.content for our CodeBlock directive:

.  render_posts:cache/posts/index4.html
N. ['sudo vim /etc/lightdm/lightdm-gtk-greeter.conf']
N. ['[base]', 'session=/usr/bin/startlxde', '...', '[userlist]', 'disable=1']
N. ['foo', 'bar', '             baz (this indented with 3 spaces and 2 tabs)', 'foobar', '    foobaz']
.  render_posts:cache/posts/index.html
N. ['sudo vim /etc/lightdm/lightdm-gtk-greeter.conf']
N. ['[base]', 'session=/usr/bin/startlxde', '...', '[userlist]', 'disable=1']
N. ['foo', 'bar', 'baz (this indented with 3 spaces and 2 tabs)', 'foobar', '    foobaz']

As you can see, we’re missing the indentation of baz. Is this a bug on our side or is this an issue with how rst2html5 parses things?

cc @Netspider, @ralsina