@gracjan I don't know.  As said, I didn't review the patch because there were too many unrelated changes.

I just stumbled on this issue, because I looked at your code to find out how to get the mtime of a file in Emacs Lisp.  I saw `file-attributes`, read its docstring, and noticed that you accessed the wrong element.  I wanted to make you aware of that, since you might have a similar code in some other Emacs Lisp project of yours.