Pull Request resolves # .

• I read the Generative AI policy and my contribution is either not created with the help of AI or is compatible with the policy and GNU/GPL 2 or later.

Summary of Changes

This pull request (PR) fixes the check of the backwards compatibility plugins in the CLI Core Update command which is performed when updating to a new major version - here Joomla 7, so that

• it does not check the wrong plugins (compat and compat6) but the right ones (compat6 and compat7)
• checks a plugin only if it exists - currently in 6.1 and 6.2 there is not yet any compat7 plugin
• changes hard-coded plugin names to using Version::MAJOR_VERSIONfor the current and Version::MAJOR_VERSION + 1 for the version-specific part of the plugin identifier (element) so that the code doesn't need to be adjusted with every new major version.

It is basically the same as PR #47807 for the pre-update check in the backend, but here for the CLI without any need for a language string change.

Testing Instructions

Preparation

This PR can only be tested when PHP CLI is available.

The numbered steps 1 to 6 below need to be done for each of these 2 tests:

• Test 1: Plugin "Behaviour - Backward Compatibility 6" disabled
• Test 2: Plugin "Behaviour - Backward Compatibility 6" enabled

Each of the tests has to start with a current 6.0-dev or latest 6.2 nightly build installation

1. In backend in the options of the Joomla Update component, set the update channnel to custom URL and enter the URL of the 7.0 nightly builds, which is https://update.joomla.org/core/nightlies/next_major_list.xml.
2. Then check for updates if no update is found immediately.
3. Then you will the get an error which is unrelated to this PR here and which is silved by PR #47807 .
4. Ignore that error and open a command shell in your Joomla root folder.
5. Then run the CLI core update command:

php ./cli/joomla.php core:update

6. Check the result.

Actual result BEFORE applying this Pull Request

Test 1: Plugin "Behaviour - Backward Compatibility 6" disabled

Updating Joomla
===============

Starting up ...
Running checks ...
Check Database Table Structure...
 1/9 [===>------------------------]  11%
                                                                                                                        
 [INFO] 3 database changes were checked.                                                                                
                                                                                                                        

                                                                                                                        
 [INFO] 39 database changes did not alter table structure and were skipped.                                             
                                                                                                                        

Check pre-conditions for a major upgrade to version 7.0.0-alpha1-dev...
 2/9 [======>---------------------]  22%
                                                                                                                        
 [ERROR] The 'Behaviour - Backward Compatibility 6' plugin is disabled.                                                 
                                                                                                                        

 9/9 [============================] 100%                                                                                
 [INFO] The pre-conditions for a major upgrade are not fulfilled.                                                       

This is wrong.

We are on Joomla 6, an update to 7 should work when the b/c plugin for the current major version 6 is disabled (as long as we do not have a b/c plugin yet for the next major version 7 which would need to be enabled).

Test 2: Plugin "Behaviour - Backward Compatibility 6" enabled

The update is performed.

This is wrong.

We are on Joomla 6, an update to 7 should not work when the b/c plugin for the current major version 6 is enabled.

Expected result AFTER applying this Pull Request

Test 1: Plugin "Behaviour - Backward Compatibility 6" disabled

The update is performed.

This is right as long as we do not have a b/c plugin yet for the next major version 7 which would need to be enabled.

Test 2: Plugin "Behaviour - Backward Compatibility 6" enabled

Updating Joomla
===============

Starting up ...
Running checks ...
Check Database Table Structure...
 1/9 [===>------------------------]  11%
                                                                                                                        
 [INFO] 3 database changes were checked.                                                                                
                                                                                                                        

                                                                                                                        
 [INFO] 39 database changes did not alter table structure and were skipped.                                             
                                                                                                                        

Check pre-conditions for a major upgrade to version 7.0.0-alpha1-dev...
 2/9 [======>---------------------]  22%
                                                                                                                        
 [ERROR] The 'Behaviour - Backward Compatibility 6' plugin is enabled.                                                  
                                                                                                                        

 9/9 [============================] 100%                                                                                                                        
 [INFO] The pre-conditions for a major upgrade are not fulfilled.                                                       

Link to documentations

Please select:

• Documentation link for guide.joomla.org:

• No documentation changes for guide.joomla.org needed

• Pull Request link for manual.joomla.org:

• No documentation changes for manual.joomla.org needed