Breaking: #67545 - PreFileAdd signal behaviour changed 

See forge#67545

Description 

In order to check whether an uploaded file exists already before uploading or to determine user preferences about present files only when needed, the final name of the file is needed. As the final name can be altered by the PreFileAdd signal, which originally always received the temporary uploaded file path as parameter, the signal will now receive an empty string in $sourceFilePath.

Impact 

All PreFileAdd slot methods that depend on the $sourceFilePath param must be adapted to handle the new empty string value.

Affected Installations 

All extensions that use the PreFileAdd signal and depend on the $sourceFilePath param.