Description

serhiy-storchaka

opened on May 7, 2026

Issue body actions

Bug report

There are several bugs which prevent generation of correct HTML:

• Comment and "processing instruction" content should not be escaped. Similar bug was fixed for XML in ElementTree ProcessingInstruction uses character entities in content #46995.
• There are more elements besides <script> and <style> whose content should not be escaped.
• <plaintext> does not have the closing tag, and its content should not be escaped.
• Empty attributes (with value None) are not supported.

Linked PRs

• gh-149489: Fix ElementTree serialization to HTML #149490
• [3.15] gh-149489: Fix ElementTree serialization to HTML (GH-149490) #150592
• [3.14] gh-149489: Fix ElementTree serialization to HTML (GH-149490) #150593
• [3.13] gh-149489: Fix ElementTree serialization to HTML (GH-149490) #150594
• [3.15] gh-149489: Fix ElementTree serialization to HTML (GH-149490) #150595
• [3.14] gh-149489: Fix ElementTree serialization to HTML (GH-149490) #150596
• [3.13] gh-149489: Fix ElementTree serialization to HTML (GH-149490) (GH-150596) #150609

Activity

1. serhiy-storchaka

   added

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   stdlibStandard Library Python modules in the Lib/ directoryStandard Library Python modules in the Lib/ directory

   topic-XML

   3.13only security fixesonly security fixes

   3.14bugs and security fixesbugs and security fixes

   on May 7, 2026
2. serhiy-storchaka commented on May 7, 2026

   

   serhiy-storchaka

   on May 7, 2026

   MemberAuthor

   More actions

   There is a question what to do with <noscript>. It's syntax depends on whether scripting was enabled.
3. serhiy-storchaka commented on May 7, 2026

   

   serhiy-storchaka

   on May 7, 2026

   MemberAuthor

   More actions

   Well, it is only issue for the parser. The generator should escape it's content, and allow subelements.
4. serhiy-storchaka

   added a commit that references this issue on May 7, 2026

   pythongh-149489: Fix ElementTree serialization to HTML

   e41d61c
5. serhiy-storchaka

   added

   3.15bugs and security fixesbugs and security fixes

   on May 8, 2026
6. serhiy-storchaka

   added a commit that references this issue on May 29, 2026

   gh-149489: Fix ElementTree serialization to HTML (GH-149490)

   bcd29e4
7. miss-islington

   added 2 commits that reference this issue on May 29, 2026

   pythongh-149489: Fix ElementTree serialization to HTML (pythonGH-149490)

   26f9c5f

   pythongh-149489: Fix ElementTree serialization to HTML (pythonGH-149490)

   6efc3f3
8. serhiy-storchaka

   added 3 commits that reference this issue on May 29, 2026

   [3.15] gh-149489: Fix ElementTree serialization to HTML (GH-149490) (G…

   2f91315

   [3.14] pythongh-149489: Fix ElementTree serialization to HTML (python…

   de5e730

   [3.14] pythongh-149489: Fix ElementTree serialization to HTML (python…

   f596830
9. serhiy-storchaka commented on May 29, 2026

   

   serhiy-storchaka

   on May 29, 2026

   MemberAuthor

   More actions

   Stopping escaping comments and "processing instruction" can create security issue if users were not ready for this, so it is not safe to backport this to released versions. Support of empty attributes looks rather like a new feature. But I think that the rest of changes are safe for backporting.
10. serhiy-storchaka

    added 2 commits that reference this issue on May 30, 2026

    [3.14] gh-149489: Fix ElementTree serialization to HTML (GH-149490) (G…

    c42e6d3

    [3.13] gh-149489: Fix ElementTree serialization to HTML (GH-149490) (G…

    b46df7f
11. serhiy-storchaka

    closed this as completedon Jun 10, 2026

Issue actions