Re: Decoding URLs input

[Eli Zaretskii <eliz@gnu.org>]

> From: Yuri Khan <yuri.v.khan@gmail.com>
> Date: Sun, 4 Jul 2021 03:16:37 +0700
> 
> I just fed it some percent-encoded sequences that I knew would result
> in invalid UTF-8 when decoded. If it were doing a full decode, I
> expected it to signal an error. It didn’t.

That's not a reliable sign that a function returns unibyte strings.
Most Emacs APIs that decode strings don't signal errors if they
encounter invalid sequences; instead, they decode those into raw
bytes.  The design principle is to support raw bytes in strings and
let the application deal with them if they are not expected.