Motivation:
In theory, all moves work the way they should. However, sometimes something might happen during the move, so that it cannot be completed successfully. Our extension should behave gracefully when that happens, and not leave broken files behind.
Task:
- If something fails during the transfer of all file information, undo the whole move.
- The only step excluded from that is the template mapping. Do not undo a move, if no template could be mapped, but instead show a (momentary) message on the new Commons file page that the template could not be mapped
- if the move was undone, show the user an error message on the original file page. Text: "The file could not be moved because <error details>"
Background:
This is part of fulfilling on wish of the German-community speaking wishlist of 2013. For details see the parent task