Podcast feed: Prevent fatals when passing invalid arg to XML parser

[tbradsha]

Closes MONOREP-148

This addresses the following fatal:

PHP Fatal error: Uncaught ValueError: DOMDocument::loadXML(): Argument #1 ($source) must not be empty in /wordpress/plugins/jetpack/15.2-a.1/_inc/lib/class-jetpack-podcast-feed-locator.php:66

I made two changes:

1. Instead of using $file->body, let's use $file->get_body_content(), which simply casts body to a string. Only available in WP 6.9 (thanks, Phan). Cast $file->body to string.
2. Return early if $xml is empty.

Proposed changes:

Other information:

• Have you written new tests for your changes, if applicable?
• Have you checked the E2E test CI results, and verified that your changes do not break them?
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Jetpack product discussion

Does this pull request change what data or activity we track or use?

Testing instructions:

• Go to '..'

[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WoA dev site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin (Jetpack), and enable the fix/jetpack/fatals_when_passing_invalid_arg_to_xml_parser branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack fix/jetpack/fatals_when_passing_invalid_arg_to_xml_parser

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[github-actions]

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[jp-launch-control]

Code Coverage Summary

Coverage changed in 1 file.

File	Coverage	Δ%	Δ Uncovered
projects/plugins/jetpack/_inc/lib/class-jetpack-podcast-feed-locator.php	21/28 (75.00%)	-1.92%	1 ❤️‍🩹

Full summary · PHP report · JS report

[Copilot]

Pull Request Overview

This PR prevents fatal errors in the podcast feed locator when handling invalid or empty XML content by adding proper validation and type casting.

Key Changes:

• Added early return when XML content is empty to prevent DOMDocument::loadXML() fatal error
• Cast $file->body to string to ensure proper type handling

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
projects/plugins/jetpack/changelog/fix-jetpack-fatals_when_passing_invalid_arg_to_xml_parser	Added changelog entry documenting the fatal error prevention fix
projects/plugins/jetpack/_inc/lib/class-jetpack-podcast-feed-locator.php	Added empty string validation and type casting to prevent XML parser fatals

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[manzoorwanijk]

Makes sense to me