Adding a Tab without an existing Channel Layout throws an error

[swierczek]

Description of the problem If a Channel doesn't have a Publish Layout created, then when viewing a saved entry with a custom Tab throws an error:

Error at https://github.com/ExpressionEngine/ExpressionEngine/blob/7.dev/system/ee/ExpressionEngine/Model/Content/Display/DefaultLayout.php#L72 because $fields[$field_id] is not set.

How To Reproduce Steps to reproduce the behavior:

1. Create a custom field with a tab as described at https://docs.expressionengine.com/latest/development/tab-files.html
2. Install the add-on/field
3. Create a new channel and don't create a Publish Layout
4. Create a new entry in that channel. The create page should load as expected. But after you click Save and it reloads the new entry, the error should appear.

Error Messages

Error Caught
Call to a member function getId() on null

ee/ExpressionEngine/Model/Content/Display/LayoutTab.php:49
Stack Trace: Please include when reporting this error

    #0 ee/ExpressionEngine/Model/Content/Display/DefaultLayout.php(73): ExpressionEngine\Model\Content\Display\LayoutTab->addField(NULL)
    #1 ee/ExpressionEngine/Model/Channel/Display/DefaultChannelLayout.php(229): ExpressionEngine\Model\Content\Display\DefaultLayout->transform(Array)
    #2 ee/ExpressionEngine/Model/Channel/ChannelEntry.php(835): ExpressionEngine\Model\Channel\Display\DefaultChannelLayout->transform(Array)
    #3 ee/ExpressionEngine/Controller/Publish/Edit.php(509): ExpressionEngine\Model\Channel\ChannelEntry->getDisplay(Object(ExpressionEngine\Model\Channel\Display\DefaultChannelLayout))
    #4 [internal function]: ExpressionEngine\Controller\Publish\Edit->entry('83676')
    #5 ee/ExpressionEngine/Core/Core.php(268): call_user_func_array(Array, Array)
    #6 ee/ExpressionEngine/Core/Core.php(124): ExpressionEngine\Core\Core->runController(Array)
    #7 ee/ExpressionEngine/Boot/boot.php(184): ExpressionEngine\Core\Core->run(Object(ExpressionEngine\Core\Request))

Environment Details:

• Version: 7.3.12
• PHP Version: 8.0.30
• Web Server: Apache

Possible Solution The solution is to create a Publish Layout for the channel. But that isn't obvious given the error message. I'd suggest either a more graceful error in this case to guide the user to create a Publish Layout manually, or to handle the error gracefully in code so it doesn't actually prevent the entry from loading.