The documentation of `tramp-connection-properties` claims:
List of static connection properties.
Every entry has the form (REGEXP PROPERTY VALUE). The regexp
matches remote file names. ...
However, the actual implementation of `tramp-get-hash-table` uses the
following code for the lookup:
(dolist (elt tramp-connection-properties)
(when (tramp-compat-string-search
(or (nth 0 elt) "")
(tramp-make-tramp-file-name key 'noloc 'nohop))
where (on current emacs) `tramp-compat-string-search` translates to a
simple `string-search` which uses REGEXP to do a simple string search
instead of a regexp search.
IMO the docstring describes the desired functionality which means that
the implementation is incorrect.
Emacs : GNU Emacs 28.0.91 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.31,
cairo version 1.16.0)
of 2022-01-09
Package: tramp (2.5.2-pre emacs-28/3dd47bde7a87bef332bd53f3e73c8d2bc64910c8)
