Windows paths are valid URLs

[konstin]

Currently, it is not possible to set a custom Python downloads JSON on Windows, as Windows paths can be valid URLs.

use url::Url;

fn main() {
    dbg!(Url::parse(r"C:\Users\Ferris\download.json"));
}

Tested by #13585 (where it is currently failing CI).

[charliermarsh]

I might suggest using split_scheme and Scheme::parse here instead of Url::parse? That's what we tend to do elsewhere.

[konstin]

To support file: URLs or to check something more specific than Url::parse?

[charliermarsh]

To check something more specific, e.g., that it's a known remote host like http or https.

[charliermarsh]

As-is, won't this erroneously tell you that remote URLs aren't supported if you use a Windows path and it fails to open?

[konstin]

Oh now I understand, good catch.

I've changed the logic to assume that one-letter protocols are Windows drives, and to also support file:// URLs while I'm at it.

[charliermarsh]

Why not just use the scheme detection code we use everywhere else?

[Gankra]

I agree with charlie, we should be allow-listing http: and https: instead of trying to detect file paths in particular.

[konstin]

wdym with allow-listing http(s)? I'm specifically only fixing the Windows case that turned out to be broken in #13585, without adding support for remote URLs.

[charliermarsh]

I think the suggestion is that this error should only show up if the scheme is http or https.

[konstin]

Make sense!