"Other files" in "Projects" displays wrong files

To reproduce:

Open "extension dialog" example from Welcome screen.
"Other files" lists the 3 source files also listed under "Headers" and "Sources".

Also, possibly related but harder to reproduce:
I have seen a generated DLL file having been added to "Other files" of a project in a subdir, when that subdir project in fact has no "OTHER_FILES" in .pro at all. In this case that .DLL is also offered in Qt Creator's "git commit" as a file to be committed (and it is not in version control).