Admin hooks of format "display#controller_name#Form" on legacy admin forms are not executed

[hugo-fasone]

Prerequisites

• I understand and accept the project's code of conduct.
• I have already searched in existing issues and found no previous report of this bug.

Describe the bug and add attachments

Admin hooks of format "display#controller_name#Form" on legacy admin forms such as "displayAdminReturnForm" are not executed.

The hook is supposed to be called here : https://github.com/PrestaShop/PrestaShop/blob/8.1.6/admin-dev/themes/default/template/helpers/form/form.tpl#L663
Here $name_controller is supposed to be the name of the controller, so for exemple "AdminReturn" in the case of the "AdminReturn" controller when we try to view a single order return. The hook should be called at the end of the form

But actually, the value of $name_controller is an empty string, so the executed hook is "displayForm" and not "displayAdminReturnForm". This behaviour is caused by these two code snippets:

https://github.com/PrestaShop/PrestaShop/blob/develop/classes/controller/AdminController.php#L2621C1-L2623C10
https://github.com/PrestaShop/PrestaShop/blob/8.1.6/classes/helper/HelperForm.php#L40

On the AdminController.php file, we see that $name_controller takes the value only if it doesn't equal null. But in the HelperForm.php file we see that $name_controller is not equal to null, it's an empty string, thus the bug : $name_controller is equal to an empty string and never takes the Tools::getValue('controller') as a value

We see in this file the smarty affectation of the "name_controller" variable used in the form.tpl file
https://github.com/PrestaShop/PrestaShop/blob/8.1.6/classes/helper/HelperForm.php#L291

This PR introduced this bug : #31514

Expected behavior

The hook "displayAdminReturnForm" should be executed at the end of a return form in backoffice (in the red rectangle on the screenshot above)

Steps to reproduce

1. Create a module that's attached to the "displayAdminReturnForm" hook
2. On this module, create a function that returns a simple string, such as "test"
3. On the "AdminReturn" in backoffice, select a return issued by a customer
4. The text "test" should appear at the end of the form (see screenshot above), but it doesn't

PrestaShop version(s) where the bug happened

Tested on 8.1.4, but was presumably introduced in 8.0.2

PHP version(s) where the bug happened

N/A

If your bug is related to a module, specify its name and its version

N/A

Your company or customer's name goes here (if applicable).

PliciWeb

[AureRita]

Hi @hugo-fasone

Thank you for your report and sorry for the time we spend to answer you, to try to reproduce your issue, can you provide us a exemple module to test it ?

waiting for your feedback