[Tab tray refactor] "+" button from list of private tab tray opens regular tab (iPad only)

[clarmso]

Steps to reproduce

1. Open a website on a regular tab.
2. Open tab tray.
3. Switch to Private Browsing mode.
4. Open a website on a private tab.
5. Open (private) tab tray.
6. Tap "+".

Expected behavior

A new private tab is opened.

Actual behavior

A new *regular tab is opened

Device & build information

• Device: iPad Air simulator iOS 17.4
• Build version: 9000 (Feb 20, 2024)
• First seen version: Since Feb 15, 2024

Notes

Attachments:

The following automated XCUITests are affected:

• testCloseAllTabsPrivateModeUndo()

Screen recording of the bug: https://github.com/mozilla-mobile/firefox-ios/assets/1740517/4a8ce1ee-5a41-4b62-b897-3dc51f616ddd

The private tab may appears as the following when the simulator is at this state. Private tabs are supposed to be purple.

┆Issue is synchronized with this Jira Task

[data-sync-user]

➤ Alina Moldovan commented:

Validated as fixed using FF v9000 (41668) and iPhone 15+ (17.4.1) & iPad Pro 4th Gen (17.2)

[data-sync-user]

➤ Diana Andreea Barladeanu commented:

Verified as fixed on v126.1 (41973), with iPad Air 3rd gen (17.5).