Multiple CDATA regressions in wp-includes

[sephr]

There is invalid XHTML at lines 2084-2097 of wp-includes/theme.php ( ​https://github.com/WordPress/WordPress/blob/3f3fe5a7ed6473e995f9b96ee4bcf36fe4c71a35/wp-includes/theme.php#L2084-L2097 )

This script block needs to be escaped with /*<![CDATA[*/ ..script content.. /*]]>*/

Otherwise it will cause rendering errors for people serving XHTML as application/xhtml+xml

This was not always like this, as 5 years ago when I made my strict XHTMl theme there were no errors. I recently re-enabled serving as application/xhtml+xml and to my surprise find this regression in the WP codebase.

[SergeyBiryukov]

Related: [31034] (for #18788).

[sephr]

Whoever made that change must not have realized that wp-includes is not only used in the admin interface.

[SergeyBiryukov]

Also related: #25863, comment:12:ticket:14226.

[sephr]

Replying to SergeyBiryukov:

Also related: #25863, comment:12:ticket:14226.

My issue is with WordPress as a platform, not the pre-installed themes. That comment is for that specific theme. My XHTML5 theme has been working absolutely fine for many years, and it seems like the intention of #18788 was only to remove CDATA in the admin interface. The patch unintentionally affected all theme content though.

[sephr]

Replying to SergeyBiryukov:

Also related: #25863, comment:12:ticket:14226.

https://core.trac.wordpress.org/ticket/14226#comment:19

XHTML is fine for other themes or child themes. They just didn't want it in the default theme.

[SergeyBiryukov]

Replying to sephr:

My XHTML5 theme has been working absolutely fine for many years, and it seems like the intention of #18788 was only to remove CDATA in the admin interface.

You're right, I guess we should restore CDATA for scripts that are loaded on front end.

[SergeyBiryukov]

FWIW, this is not a 4.4 regression, wp_customize_support_script() was added in 3.4 without CDATA: [20893].

[sephr]

Can you merge this and #36037 into a general XHTML regressions bug? I'll submit a patch for the few applicable areas.

[subharanjan]

Added CDATA

[sephr]

Fix wp-includes CDATA

[sephr]

I can't edit issues so it would be nice if someone with the permissions could change this issue's title to 'multiple CDATA regressions in wp-includes' to better organize this, instead of splitting it up into one ticket per file.

[sephr]

I also changed 2 comments that said CDATA is not necessary for HTML5. CDATA sections are not necessary for non-XHTML, and the HTML5 doctype has no bearing on how the browser parses them.

[sephr]

(fix missing .firstChild on one line)

[sephr]

Simplified wp-playlist.js changes

[sephr]

For my first patch I implemented some CDATA normalization that directly accessed the contents of a CDATA node, but I decided that this simpler regex on html() is better. As far as I can tell this is the minimum amount of changes necessary.

[SergeyBiryukov]

#36037 was marked as a duplicate.

[sephr]

Missed one in functions.php

[sephr]

There was one I missed in wp-includes/functions.php

[mikeschroder]

Punting due to lack of movement on ticket and timeframe for 4.5.

@SergeyBiryukov, feel free to re-milestone/commit if it looks good for 4.5.

[dd32]

#42972 was marked as a duplicate.

[sephr]

I will re-do this patch if someone on the dev team is willing to assist with review & merge.