Fulltext index is not updated when removing a single attached files in the files tab

Steps to reproduce:

1- create an empty file on your drive named "uniqueword1.txt" and with content "uniqueword2"
2- create a document of type File with no main attachment and title "Test File document"
3- go to the "Files" tab of "Test File document" and attach "uniqueword1.txt"

By using the search box, you should be able to find "Test File document" with both "uniqueword1.txt" and "uniqueword2" as query words. Everything is fine so far.

4- go back to the "Files" tab of "Test File document" and click the red minus button to delete the "uniqueword1.txt" file attachment.
5- query both on "uniqueword1.txt" and "uniqueword2" in the nuxeo search box

Expected: "Test File document" does not show up in the search results
Observed: "Test File document" does show up in the search results

The culprit seams to be PersistenceContext#findDirtyDocuments(Set<Serializable> dirtyStrings, Set<Serializable> dirtyBinaries) that ignores documents where an element of a complex property is deleted.