Starting with the implementation of PR #750 in ezpublish-legacy, eZ Image Editor stopped working.

eZIE works with the cache directory for creating copies and thumbnails of the images. When making the initial copies, the paths of the copies are stored in the ezdfsfile table. When later trying to fetch those copies (by file path), the files are searched in the ezdfsfile_cache table, which can't be found there, breaking the Image Editor.

The error is actually caused by a mistake in the implementation of

that prevents copy from working if source and destination aren't of the same type (storage/cache).