in #352, but I'm worried that there's some over-reach here.
Currently only implemented as a warning, with no switch to turn it off, which
maintains current behavior other than the warning.
In general, we're treating any string as a complete URL, rather than breaking
URL's into component parts. Thus the `IsURLCodePoint()` check includes a few
other generic characters that strictly speaking aren't valid codepoints, but
are valid as escape characters and delimiters.
When addressing #338, I ran into a similar situation in not having a built-in
method to separate path components (although a simple generalized solution was
good enough in that case).
Thus without introducing a new structure and functions to deconstruct a URL
into scheme, authority, path, parameters, etc., some variation of this patch
will have to be used to address #352.
fd77312175