[development] Allow existing files to be attached

Hello, Is there a module that allows users to attach existing files to node? The upload module only allows you to attach file from your computer, not existing files in /files. Isn't it a very common use case ? The upload ui could be like this : - Upload a file from your computer (current upload box) or - Attach an existing file from your site (some sort of ajax search system + file path text input form as a fallback for js disabled browsers) I can work on this as a contrib module, but it's strange this has not been made already. I want a compatible solution with core upload module. Did I miss something? I wanted to ask before working on it so I don't reinvent the wheel. Thank you Philippe