TYPO3 Core

With switching to ajax actions for the all configuration panel, several issues have been introduced

1. AdditionalConfiguration.php values lead to an error when saving

set a value in AdditionslConfiguration.php

$GLOBALS['TYPO3_CONF_VARS']['FOO']['BAR']='baz';

go to settings -> global settings -> save

Expected: Saving works (worked in 8.7 and below)
Actual: "Something went wrong" is shown

2. AdditionalConfiguration.php values AND values from extensions's ext_localconf.php are considered when saving

set this value in AdditionslConfiguration.php

$GLOBALS['TYPO3_CONF_VARS']['MAIL']['transport'] = 'mbox';

Make sure this is set to a different value in LocalConfiguration.php

go to settings -> global settings -> save

Expected: "Nothing to update" is shown
Actual: MAIL/transport -> New value (and far more severe: FE/defaultTypoScript_setup -> New value)

3. Values in New Value messages are not HTML encoded

• go to settings -> global settings
• Change value MAIL/transport to "<h1>mbox</h1>

Expectation: See the actual value
Actual: "mbox" is shown, formatted as HTML headline

Remark: <script> also works