Hi there, I have some posts imported from another forum software with line breaks in headings. These are shown correctly in the post preview, but they are not rendered as headings in the final baked post. I’m seeing this issue on my forum updated yesterday and also here on Discourse Meta:
Heading test with line breaks
Normal paragraph.
Heading with no line breaks
It’s leaving the <h2> blank and is wrapping the text after that in <p> :
<h2 dir="ltr">
</h2><p dir="ltr">Heading test with line breaks</p>
I’m 99% sure that this is a recent regression, as I specifically checked headings in imported posts from the same user during the migration process, and the user and I both remember that they were rendered correctly.
2개의 좋아요
sam
4월 11, 2023, 1:16오전
3
Hmm given the ltr stuff there @Osama could this be related to the CSS flipper we recently added?
2개의 좋아요
Osama
4월 12, 2023, 1:56오전
4
I don’t think so because the final/cooked HTML of the post is wrong and the CSS flipper (whether the old or the new one) isn’t involved at all in the post cooking process.
^ the text inside the <p> should be inside the <h2> and there should be no <p> at all (I think).
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selase
5월 8, 2023, 6:15오후
5
This seems to happen during cooking, specifically markdown parsing.
sanitized = markdown(working_text, options)
doc = Nokogiri::HTML5.fragment(sanitized)
add_nofollow = !options[:omit_nofollow] && SiteSetting.add_rel_nofollow_to_user_content
add_rel_attributes_to_user_content(doc, add_nofollow)
strip_hidden_unicode_bidirectional_characters(doc)
sanitize_hotlinked_media(doc)
add_mentions(doc, user_id: opts[:user_id]) if SiteSetting.enable_mentions
scrubber = Loofah::Scrubber.new { |node| node.remove if node.name == "script" }
loofah_fragment = Loofah.fragment(doc.to_html)
loofah_fragment.scrub!(scrubber).to_html
Passing a header with linebreaks to PrettyText.markdown returns with the content of header wrapped in a p tag.
And then during scrubbing, the paragraph get’s extracted out out of the header tag resulting in the following:
I suppose this happens since a paragraph in a header tag isn’t spec compliant?
I’m still reviewing the markdown parser code to figure out why the content is being wrapped in p tag in the first place.
2개의 좋아요
sam
5월 9, 2023, 12:02오전
7
Oh this is very related to:
Took a quick look out of curiosity. It looks like an issue with the Nokogiri library. [image]
From what uses Discourse here:
Loofah.fragment uses Nokogiri’s HTML4 parser.
This could be fixed using Loofah.html5_fragment as long as Nokogiri >= 1.14.0 and Loofah >= 2.21.0. Discourse already uses Nokogiri::HTML5.fragment; that would make sense.
Note: Loofah 2.21.0 is not yet released; currently in RC1.
I am OK to wait a few more weeks for Loofah to release
Will shoot out a Tweet to Mike to mention this popped up.
2개의 좋아요
Hi there, thanks for looking into this. HTML doesn’t care about line breaks, so technically this is correct:
<h2>
Heading test with line breaks
</h2>
It simply seems to be a problem of the Markdown parser running after/inside the HTML parser, which is generating <p> tags for the line returns.
1개의 좋아요
nat
6월 20, 2023, 12:40오후
11
Hey there, we’ve fixed this with
https://github.com/discourse/discourse/pull/21522
as seen here:
Heading test with line breaks
Normal paragraph.
Heading with no line breaks
8개의 좋아요
Glad to hear, thanks @nat ! Does this require rebaking posts?
2개의 좋아요
nat
6월 20, 2023, 1:21오후
13
Yes, it does require a rebake — we can’t do it for you automatically with this fix since it’s an expensive operation.
3개의 좋아요
nat
6월 22, 2023, 12:40오후
14
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