Fix regex/param matching for paths with dots

[6543]

Fixes #758

based on #811

[VojtechVitek]

FYI, we can't run the CI, since this PR is still in draft.

[VojtechVitek]

This looks good. Please rebase the PR to kick off CI

[VojtechVitek]

just keep the old code working

What does this mean? I don't follow.

[VojtechVitek]

Actually, this branch doesn't work well for the bellow snippet (unlike master branch).

package main

import (
	"fmt"
	"net/http"
	"net/http/httptest"

	"github.com/go-chi/chi/v5"
)

func main() {
	mux := chi.NewMux()
	mux.Get("/{param:[^.]+}.{ext:.+}", func(w http.ResponseWriter, r *http.Request) {
		param := chi.URLParam(r, "param")
		ext := chi.URLParam(r, "ext")
		_, _ = fmt.Fprintf(w, "param=%s, ext=%s", param, ext)
	})

	rec := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/param.json", nil)
	mux.ServeHTTP(rec, req)

	fmt.Printf("code: %d, body: %s\n", rec.Code, rec.Body)

	rec = httptest.NewRecorder()
	req = httptest.NewRequest(http.MethodGet, "/param.tar.gz", nil)
	mux.ServeHTTP(rec, req)

	fmt.Printf("code: %d, body: %s\n", rec.Code, rec.Body)
}

I'm going to close this PR. I think r.Get("/{param:[^.]+}.{ext:.+}", ... is a sufficient workaround.

Thanks for your work on this!