I've been using iPhoto for some time but I had disabled Copy items to the iPhoto Library option at the beginning. Now I decided to let iPhoto manage all my pictures.
I enabled Copy items to the iPhoto Library option but, unfortunately, it only works for new files. I would like iPhoto to import files that are referenced from the library but stored outside of it (in external directories).
The easiest workaround would be to delete all pictures in iPhoto and import them again with Copy items to the iPhoto Library option enabled but I have edited some pictures in iPhoto and those alternative versions would be lost then.
How to force iPhoto to physically import the already referenced files to the library?