[Leica] OT: Yosemite - Photo - Help

[photo.philippe.amard at gmail.com (Philippe)]

Hi All, 

A friend using Photo (Yosemite) wants to re-sort photos he had "catalogued" 
in I-photo - in short moving pixies from one folder/event (A) to another one 
(B) where they belong.
This can be done by selecting the previews in A and moving them to the right 
folder B or C or D alright.
Yet, and this is the problem, when you "suppress" the files from the 
original folder A, they also disappear from the new destination B.

What I have found to work is, after moving the files, create a duplicate in 
destination folder B, or C etc.. This of course results in two copies of the 
file in the destination folder. I then delete the original file in folder A, 
which results in the copy being deleted in B as well. And the duplicate 
remains in B. Hurray!

However, the process is (very) long and tedious, with some risks of losing 
files by accident.

So here is my question to experienced mac users : is there a shorter way to 
simply get files reorganized ? kind of just moving the files as in the 
finder ?

Thanks in anticipation for your precious helps.

Amities
Philippe