Fix encoding of MSGID and SD-ID fields of StructuredDataMessage to XML

[vy]

No description provided.

[Copilot]

Pull request overview

This PR fixes XML output generation for StructuredDataMessage by ensuring the <type> (MSGID) and <id> (SD-ID) element contents are properly XML-escaped, preventing malformed XML when these fields contain reserved characters or invalid XML code points.

Changes:

• Escape XML for StructuredDataMessage’s <type> and <id> fields using StringBuilders.escapeXml(...).
• Add regression tests covering reserved XML characters, quotes, non-BMP characters, and invalid XML characters in type and id.
• Add a changelog entry documenting the fix.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/changelog/.2.x.x/fix-StructuredDataMessage-XML-encoding.xml	Documents the XML encoding fix in the 2.x.x changelog stream.
log4j-api/src/main/java/org/apache/logging/log4j/message/StructuredDataMessage.java	Escapes <type> and <id> values in XML formatting to produce valid XML.
log4j-api-test/src/test/java/org/apache/logging/log4j/message/StructuredDataMessageTest.java	Adds tests ensuring type/id XML encoding and invalid character handling are correct.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[ppkarwasz]

LGTM! 💯

I guess you can not create test cases with control characters forbidden in XML 1.0, because StructuredDataMessage will throw, right?

[vy]

I guess you can not create test cases with control characters forbidden in XML 1.0, because StructuredDataMessage will throw, right?

No, it doesn't, yet. It will start throwing after #4103.