Text Filter mangles HTML when attribute value contains a special character

[ryandemmer]

Steps to reproduce the issue

1. In System -> Global Configuration -> Site, set Default Editor to Editor - None.
2. In System -> Global Configuration -> Text Filters, set Filter Type for the Super Users group to Default Forbidden List.
3. Click Content -> Articles -> New to create a new article.
4. Paste in the content below. Note the (valid) special character in the href attribute value.

<a href="https://www.ikea.com/gb/en/p/birkelånga-tray-patterned-multicolour-grey-green-40537947" target="_blank">BIRKELÅNGA</a>

5. Click Save

Expected result

The article content should remain intact as the HTML is valid.

Actual result

The content becomes

a href="https://www.ikea.com/gb/en/p/birkelånga-tray-patterned-multicolour-grey-green-40537947&quot;&quot;"BIRKELÅNGA</a>

once filtered and saved. The first < and > from the <a> tag are removed and the last " of the attribute value is encoded.

System information (as much as possible)

Joomla 4.2.4
Browser (Any)
PHP 8.0.14

Additional comments

When the Text Filter Filter Type is set to No Filtering, this issue does not occur, and the content is saved correctly.

[ryandemmer]

This appears to only occur when the special characters are in the href attribute value. For example, the following link, where the special caharacters are in the title attribute value, the Text Filter does not affect the HTML:

<a href="https://www.ikea.com/gb/en/p/birkelanga-tray-patterned-multicolour-grey-green-40537947" title="BIRKELÅNGA">BIRKELÅNGA</a>

Further investigation shows that when a special character is in the src attribute value of an <img> tag for example, a FatalError Error: Maximum execution time of 30 seconds exceeded is generated with reference to libraries/vendor/joomla/string/src/phputf8/mbstring/core.php on line 94

[MacJoom]

I can confirm this, only with my system the <img> tag is mangled as well, no Fatal Error, and strange enough <img gets ig

[SharkyKZ]

joomla-framework/filter#50.

[ryandemmer]

This appears to be fixed in this PR - joomla-framework/filter#50

[MacJoom]

Yes i have successfully tested joomla-framework/filter/pull/50 - closing this issue then

[deltapapa01]

Hi,
Bug is still there: #39515