bug#74879: 30.0.92; trusted-content-p and trusted-files cannot be used for non-file buffers

[Daniel Mendler]

Thank you for the recent addition of `trusted-content-p'. Is there a
possibility to use `trusted-content-p' in buffers which are not backed
by a file? I use Flymake in *scratch* or similar buffers and it seems
that this won't continue to work given that `trusted-content-p' needs a
`buffer-file-truename'.

My suggestion would be to replace `trusted-files' by a
`trusted-buffer-function' which is a predicate function or a list of
functions. The functions could then check a custom list of trusted files
or a custom list of trusted buffers.

Alternatively offer `trusted-files', `trusted-buffers' and
`trusted-buffer-function`? `trusted-buffers' could for example rely on
`buffer-match-p`.

Daniel