bug#57856: 28.2; bookmark context strings in encrypted files

[Lars Ingebrigtsen]

Michael Albinus <michael.albinus@gmx.de> writes:

> auth-source-file-name-p could scan the auth-sources declarations for a
> file based backend, and return t for such files. Shouldn't be too hard
> to implement (oops, do I offer to volunteer?)

Yes, those were the heuristics I were alluding to.  😀  But I was
thinking about packages that say

(let ((auth-sources ...))
  (auth-source-search ...))

and we'd have no idea how to identify those files.