Video sitemap description: change the XSL Stylesheet to display the HTML

[htdat]

Fixes #9546

Changes proposed in this Pull Request:

• First, I thought this a bug and tried a fix. But this comment Remove HTML tags in the description column of video sitemaps #13236 (comment) suggested this enhancement as Video Sitemap: description should filter out HTML tags  #9546 is not the issue itself.
• By adding disable-output-escaping='yes', humans can see rich texts with HTML rather than HTML-escaped tags.

Is this a new feature or does it add/remove features to an existing part of Jetpack?

• This is just to enhance the way we display video sitemap descriptions to humans.

Testing instructions:

• Upload a new video to Media Libary
• Add the description of the video, which includes HTML tags like <strong>Description</strong> with <a href="https://github.com/Automattic/jetpack/issues/9546">HTML tags</a>.
• Check https://domain.com/video-sitemap-1.xml
• Make sure the description of this video is displaying correctly without HTML-escaped tags: Description with HTML tags.

Proposed changelog entry for your changes:

• Sitemaps: Improve the display of video sitemap description with HTML tags.

[matticbot]

Caution: This PR has changes that must be merged to WordPress.com
Hello htdat! These changes need to be synced to WordPress.com - If you 're an a11n, please commandeer, review, and approve D31677-code before merging this PR. Thank you!

[jetpackbot]

Thank you for the great PR description!

When this PR is ready for review, please apply the [Status] Needs Review label. If you are an a11n, please have someone from your team review the code if possible. The Jetpack team will also review this PR and merge it to be included in the next Jetpack release.

Scheduled Jetpack release: September 3, 2019.
Scheduled code freeze: August 27, 2019

Generated by 🚫 dangerJS against 8fa1d91

[jeherve]

This seems to work well in my tests. 👍

[mdawaffe]

What happens when there's "weird" HTML in the description. Images, for example? Does the output look ugly to humans?

Should we run the description through kses?

[htdat]

What happens when there's "weird" HTML in the description. Images, for example? Does the output look ugly to humans?

Yeah, interesting case, which I have not thought of yet! I've tried all possible tags when editing a media file.
It's not as nice as without images tags. However, I think the result is acceptable and not too ugly for humans. See below.

Should we run the description through kses?

We can do that but we may lose the visibility of other HTML tags to search engines.

I would vote not doing this :D

My detailed test

Description HTML code

<strong>Content</strong> with <a href="https://github.com/Automattic/jetpack/issues/9546">HTML tags</a>.

<img src="https://videos.files.wordpress.com/K3mDX6U2/testing_reuter_hd.original.jpg" alt="img descriptions" />

<code>php-code</code>

<blockquote>quote line 01
quote line 02</blockquote>

<ul><li>Bullet 01</li><li>Bullet 02</li><li>Bullet 03<br><br></li></ul>

This is the result in 100% browser size:

This is the result in 75% browser size:

[matticbot]

htdat, Your synced wpcom patch D31677-code has been updated.

[mdawaffe]

I tweaked the stylesheet in 8fa1d91 to limit the size of images.

I'm fine merging this. Let's be clear with the user reporting the issue, though, that the HTML tags (including the wrapping <p> tags) are normal and expected: search engines will do the right things with them, and the sitemap XML files are not meant to be human readable (though we try to make them look nice all the same).

Firefox, for example, ignores the disable-output-escaping attribute in the XSLT, so this PR does not change the human view of the sitemap for humans using Firefox.

[kraftbj]

r206613-wpcom