Deprecation: #70316 - Frontend basket with recs 

See forge#70316

Description 

The TypoScriptFrontendController has a basic mechanism to automatically register session data if the GET/POST variable recs is given. This has been deprecated. This additionally obsoletes the configuration variable $GLOBALS['TYPO3_CONF_VARS']['FE']['maxSessionDataSize'] which has been deprecated, too.

Impact 

Handling baskets or other session data in recs throws a deprecation warning.

Affected Installations 

Extensions with a legacy that rely on this automatic basket (tt_products for example) should be adapted. Searching extensions for string recs should reveal affected parts.

Migration 

Use the session functions setKey() and getKey() of $GLOBALS['TSFE']->fe_user directly to store session data like basket information from within the extension.