Bug 431416 - Markdown text not displayed after unclosed HTML tag.
Summary: Markdown text not displayed after unclosed HTML tag.
Status: RESOLVED UPSTREAM
Alias: None
Product: markdownpart
Classification: Frameworks and Libraries
Component: general (other bugs)
Version First Reported In: unspecified
Platform: Manjaro Linux
: NOR normal
Target Milestone: ---
Assignee: Friedrich W. H. Kossebau
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-01-11 03:02 UTC by Jan Felix Langenbach
Modified: 2021-01-17 21:41 UTC (History)
0 users

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


Attachments
Screenshot of Issue (50.45 KB, image/png)
2021-01-11 03:02 UTC, Jan Felix Langenbach
Details

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Description Jan Felix Langenbach 2021-01-11 03:02:47 UTC
Created attachment 134727 [details]
Screenshot of Issue

SUMMARY
When a markdown document contains a raw HTML tag (e.g. <p>) that is neither self-closing (<p />) nor followed by a closing tag (</p>), all text and headings after this point are not displayed in the preview. Only very few constructs are displayed at all, including the contents of fenced or indented code blocks and the bullet points of ordered and unordered lists, but not the actual list items.

This even happens when the offending tag is enclosed in another properly closed tag like <div>...</div> or when it is commented out using <!-- ... -->. The latter seems particularly strange to me.

STEPS TO REPRODUCE
1. Create a markdown file containing the following:

    # Before Tag
    Text before tag.

    <p>

    # After Tag
    Text after tag.
    ```
    code after tag
    ```

2. Display the file in markdownpart, i.e. using the document preview of Kate.

OBSERVED RESULT
The heading ”After Tag” and the text “Text after tag.” is not displayed. See the attachment for a screenshot.

EXPECTED RESULT
The part of the document after the unclosed tag is rendered like the part before the tag.

SOFTWARE/OS VERSIONS
Linux Version: Manjaro Linux 20.2.1
KDE Plasma Version: 5.20.4
KDE Frameworks Version: 5.77.0
Qt Version: 5.15.2
Comment 1 Friedrich W. H. Kossebau 2021-01-17 21:41:43 UTC
Thanks for the report. Sadly this is nothing we can do about "by design", as markdownpart delegates all the hard work to Qt' QTextDocument and its markdown support. See https://doc.qt.io/qt-5/qtextdocument.html#setMarkdown and https://invent.kde.org/utilities/markdownpart/-/blob/master/src/markdownpart.cpp#L186

Sadly so far it is unclear whether there will be further FLOSS releases of Qt 5.15 or when KDE software will go Qt6 (possibly once Qt 6.2 is out this summer), so the effect of reporting that bug to Qt is unclear for now.

If this bug annoys you, a workaround might be to use the (though now deprecated) kmarkdownwebview kpart instead, if Manjaro still holds that around (see https://invent.kde.org/utilities/kmarkdownwebview/)