Re: `file-relative-name' for compressed files

[Michael Albinus]

Richard Stallman <address@hidden> writes:

>     > It seems that TRAMP's `tramp-file-name-regexp-unified' ("\\`/[^/:]+:")
>     > should be reworked to account for its extended filename syntax.
>
>     Instead of trusting that a regexp in file-name-handler-alist matches
>     the "remote" part of a filename (that's not documented this way), it
>     would be more clean to ask explicitely for it. Maybe a new function:
>
> That solution would work, and if no smaller change will work, we can
> do it that way.  But it would be nice if we could fix this without
> changing the larger structure.  Can someone see if that can be done?

`tramp-file-name-regexp-unified' is already complete covering the
remote part of a filename, that's not the problem.

There is another handler `tramp-completion-file-name-handler' which
comes first. Because of syntax ambiguity of Tramp filenames, it covers
valid Tramp filenames as well. "/ssh:foo" can be the file "foo" on the
host "ssh" as well as the (to be completed) string meaning method
"ssh" accessing host "foo".

Obviously, the regexp for `tramp-completion-file-name-handler' must
handle such cases. And therefore it is not suited for the test
performed in `file-relative-name', where it is assumed that the regexp
of a handler covers the complete remote part of a filename.

Best regards, Michael.