There is a problem and I fixed it by rewriting a bunch of code myself because I need similar code.

remove-dot-segments:
You cannot split-and-decode-uri-path and then encode-and-join-uri-path.
Those are terrible functions that don't work on all URIs.
URI schemes are allowed to specify that certain reserved characters (sub-delims) are special.
In that case, a sub-delim that IS escaped is different from a sub-delim that IS NOT escaped.

Example input to your remove-dot-segments:
(resolve-relative-reference (string->uri-reference "/") (string->uri-reference "excitement://a.com/a!a!%21!"))
Your wrong output:
excitement://a.com/a%21a%21%21%21

One solution would be to only percent-decode dots. Because dot is unreserved, that solution doesn't have any URI equivalence issues.
But I still think decoding dots automatically is a bad, unexpected side-effect to have.
I rewrote this function so that it:
- works on both escaped and unescaped dots
- doesn't unescape any unnecessary characters

The test suite no longer needs to check for incorrect output either:
> ;; The test suite checks for ';' characters, but Guile escapes
> ;; them in URIs. Same for '='.

----

resolve-relative-reference:
I rewrote this procedure so it is shorter.
I also added #:strict? to toggle "strict parser" as mentioned in the RFC.

- Nathan