I added a document to shared folder and deleted the original file - what happens?

If you add a document to your own private folder and then add it to a shared folder, the deletion of the document in your personal folder in which you uploaded the document originally will automatically delete it in the shared folder:

Who can add documents to a shared folder?    

In order to add a document to a shared folder, you need to have editing permissions for the draft, if it is shared with you and the folder must be either shared with you or created by you.