Call to hook_menu_breadcrumb_alter() is incompatible with the way core calls that alter hook

Problem/Motivation

panels_breadcrumbs calls hook_menu_breadcrumb_alter() like this:

$breadcrumb_info_end = end($breadcrumbs_info);
drupal_alter('menu_breadcrumb', $breadcrumbs_info, $breadcrumb_info_end);

It's passing the last item in the breadcrumbs array to the 2nd argument of hook_menu_breadcrumb_alter().

However, core always passes the menu item of the current page in that argument!

If you look at the API documentation for this alter hook, it says:

Parameters

$active_trail: An array containing breadcrumb links for the current page.

$item: The menu router item of the current page.

https://api.drupal.org/api/drupal/modules%21system%21system.api.php/func...

This is confirmed by looking at the code for menu_get_active_breadcrumb() in 'includes/menu.inc':

https://git.drupalcode.org/project/drupal/-/blob/7.x/includes/menu.inc#L...

Unfortunately, the way 'panels_breadcrumbs' is calling hook_menu_breadcrumb_alter() could mess up some contrib modules that are expecting that 2nd argument to be the menu item for the current page like when core calls it. I personally encountered this with the Rules Link module.

Steps to reproduce

n/a

Proposed resolution

Pass the menu item for the current page as the 2nd argument! Patch incoming :-)

Remaining tasks

1. Write patch
2. Review
3. Merge!

User interface changes

None.

API changes

None in panels_breadcrumb, but other module will a receive different value for the 2nd argument of hook_menu_breadcrumb_alter(), but this value will be consistent with the way core calls that hook.

Data model changes

None.