Breaking: #96212 - Alt text is enforced for custom login logos 

See forge#96212

Description 

To improve the accessibility of the login screen, the alt attribute has been added to the login logo in forge#92628. In case installations use a custom login logo, configured in $GLOBALS['TYPO3_CONF_VARS']['EXTENSIONS']['backend']['loginLogo'] , it had also been possible to add a corresponding "alt" text for it with $GLOBALS['TYPO3_CONF_VARS']['EXTENSIONS']['backend']['loginLogoAlt'] .

In case a custom logo was used, but no custom "alt" text configured, the alt attribute was omitted. This has changed. The alt attribute is now always added to the login logo. In case a custom logo is used, but no custom "alt" text defined, TYPO3 now automatically falls back to a default "alt" text.

Impact 

The alt attribute is now enforced for the login logo.

Affected Installations 

All installations using a custom login logo, while not defining a corresponding "alt" text.

Migration 

Add a corresponding "alt" text with $GLOBALS['TYPO3_CONF_VARS']['EXTENSIONS']['backend']['loginLogoAlt'] .