Dont crash if we can't start a session when a file path doesnt exist

[ufundo]

Before

CRM_Core_Config_MagicMerge tries to put warnings about file path issues into the session.

If a situation arises where the warnings are the root cause of not being able to init the session, the system crashes. Users get an error about not being able to start the session (but no immediate indication this is because of the file path issues).

After

If there's an error with putting the warnings into the session, we print them to the screen and then continue.

The user gets the warning, which is more useful to them. They may get subsequent warnings.

Technical details

Potentially this would be good behaviour generally, and could live in CRM_Core_Session::setStatus - but felt a bit safer to restrict to these specific warnings (which have a specific relevant example with Standalone).

Comments

For an example:

On a Standalone install, remove your custom extensions directory and make its parent directory unwriteable so the server can't recreate it ( e.g. mv web/upload/ext web/upload/ext.moved && chmod a-w web/upload). You get a crash about not having the Standalone SessionHandler (because the Standaloneusers extension that manages sessions can't be initialised, in turn because the Extension system can't boot up, because the config loading crashes at this point).

[civibot]

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[artfulrobot]

tested, works as described. MErging thanks @ufundo