Undefined array key name encountered in get_vendor() function

[nicohell]

Prerequisites

• I have searched for duplicate or closed issues
• I can recreate the issue with all plugins disabled

Describe the issue

Undefined array key name encountered in get_vendor() function

What browser(s) are you seeing the problem on?

No response

What version of PHP are you using?

8.2.x

What version of Roundcube are you using?

1.6.9

JavaScript errors

No response

PHP errors

On line 661 of file program/lib/Roundcube/rcube_imap.php the test $vendor = (string) (!empty($ident) ? $ident['name'] : ''); returns Undefined array key "name"
Here are the datas received in $ident :

array (
  'NAME' => 'Zimbra',
  'VERSION' => '9.0.0_GA_4612',
  'RELEASE' => '20240412104050',
  'USER' => 'courrier@...',
  'SERVER' => 'fd376667-0000-4282-ac83-09617f120abc',
)