slug field in records causes exceptions

[dmitryd]

Bug Report

Prerequisites

• Can you reproduce the problem on TYPO3 v8.7 LTS
• Can you reproduce the problem on TYPO3 v9.5 LTS
• Did you perform a cursory search to see if your bug or feature is already reported?

Description

Sometimes when editing a tag an exceptions happens. Condition for the exception is that the page with the same uid as the tag uid does not exist.

Exception message: #1534710048 TYPO3\CMS\Core\Exception\SiteNotFoundException. No pseudo-site found in root line of page 255

Stack trace:
in /home/app/web/typo3/sysext/core/Classes/Site/PseudoSiteFinder.php line 179
at TYPO3\CMS\Core\Site\PseudoSiteFinder->getSiteByPageId(255, array())
in /home/app/web/typo3/sysext/core/Classes/Routing/SiteMatcher.php line 210
at TYPO3\CMS\Core\Routing\SiteMatcher->matchByPageId(255)
in /home/app/web/typo3/sysext/core/Classes/Compatibility/PseudoSiteTcaDisplayCondition.php line 79
at TYPO3\CMS\Core\Compatibility\PseudoSiteTcaDisplayCondition->isInPseudoSite(...)

The reason for this is that PseudoSiteTcaDisplayCondition is for pages table only. It cannot be used for any other types of record. It is quite clear from the comment at the top of the class:

A display condition that returns true if the page we are dealing with is in a page tree that is represented by a PseudoSite object.

This is used to suppress the 'slug' field in pseudo site page trees when editing page records and to show the alias field.

Steps to Reproduce

1. Make sure that a tag has uid and there is no page with such uid in the installation
2. Try to edit the tag

Expected behavior: Tag can be edited

Actual behavior: Exception as described above

Versions

TYPO3 9.5.5
blog: 9.1.1