There are some situations where an upgrade wouldn't be supported, even though the noUpgrade bool isn't set. So when handling the errors that are caused by this, when attempting an upgrade, it shouldn't lead to some sort of offline-message/restart/warning/etc...
I added some checks on specific errors related to this and return a 501 (Not Implemented) response instead, in case of an "UpgradeUnsupported"-error. Additionally, on the GUI-side, the 501-response is now not to be considered an error to act upon.
The restore function of Trash Can ran a rename at the end regardless of whether there was anything to rename. In this case, when the file-to-be-restored did not exist in the destination folder, this resulted in an error. I added a simple check, keeping track of whether the file existed prior to restoring it in the destination folder and depending on this value it will now return nil after the restoration to prevent the renaming function to kick off. Added a test for this specific edge-case as well.
The cleaning logic in util.go was used by Simple and Trashcan but only
really suited Trashcan since it works based on mtimes which Simple does
not use. The cleaning logic in util.go was moved to trashcan.go.
Staggered and Simple seemed to be able to benefit from the same base so
util.go now has the base for those two with an added parameter which
takes a function so it can still handle versioner-specific logic to
decide which files to clean up. Simple now also correctly cleans files
based on their time-stamp in the title together with a specific maximum
amount to keep. The Archive function in Simple.go was changed to get rid
of duplicated code.
Additionally the trashcan testcase which was used by Trashcan as well as
Simple was moved from versioner_test.go to trashcan_test.go to keep it
clean, there was no need to keep it in a separate test file
Eric P