PHP 8 Deprecated function: Optional parameter $input declared before required parameter $form_state is implicitly treated as a required parameter in include_once()

[jenlampton]

Description of the bug

I'm running a backdrop site on php 8.1 with deprecation warnings enabled, and I'm seeing a handful of these:

Deprecated function: Optional parameter $input declared before required parameter $form_state is implicitly treated as a required parameter in include_once() (line 1509 of backdrop/docroot/core/includes/bootstrap.inc).

These functions called via bootstrap.inc can be hard to track down...
Searching for $input before $form_state in function definitions returns a set of Form API value callbacks, all from core:

$value_callback($element, $input, $form_state);

Such as:

• file_field_widget_value()
• file_managed_file_value()
• form_type_image_button_value()
• form_type_textarea_value()
• form_type_textfield_value()
• list_boolean_allowed_values_callback()

Should we check all these to make sure that there are no optional items before required?

Steps To Reproduce

To reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'

Actual behavior

PHP warnings about deprecations

Expected behavior

No warnings :)

Additional information

Add any other information that could help, such as:

• Backdrop CMS version: 1.24.0
• PHP version: 8.1

[argiepiano]

Hi @jenlampton. I've checked those functions, but none of of them have an optional $input before $form_state. The culprit may be somewhere else. I'm using Backdrop with PHP 8.1 and am not seeing these messages (we have been fixing several of them in the past). I wonder if perhaps this is happening in a contrib module you have installed?

I'm searching core and several contrib modules using the following regex pattern
/\$input = (.*), \$form_state(,|\))/

and am not finding any so far.

[laryn]

@jenlampton If you have a copy of the site running locally and have xdebug installed you should be able to view the call stack to see what is firing before these warnings.

[kiamlaluno]

Does that error happen with only Backdrop installed, or are there contributed modules installed?

Line 1509 is part of backdrop_load(). If the error is caused by Backdrop core, there are 22 functions/methods that call backdrop_load().