Windows file URI parsing yields an invalid path with a leading slash

[Sc3l3t0n]

Zig Version

0.14.1

Steps to Reproduce and Observed Behavior

When trying to parse a Windows file path URI, the resulting value of the struct field path is not valid.

const path_uri = "file:///C:/Users/someone";
const uri = try std.Uri.parse(path_uri);

// uri.path.percent_encoded contains "/C:/Users/someone"
try std.testing.expectEqualStrings("/C:/Users/someone", uri.path.percent_encoded);

Expected Behavior

The parser should strip the leading slash when converting a Windows file URI. In this example, the path field should only contain "C:/Users/someone" (without the trailing /).

[castholm]

Related: I have an open PR for that fixes instances of this problem in the package manager: https://github.com/ziglang/zig/pull/21931/files#diff-2c77dd01fefd6d4d63c3172a98f14d2f27a503d9ffda851258e8d62b778aa354R985-R994

I think this will be a common enough problem/footgun for users that it probably deserves some kind of handling in the standard library. In addition to the Windows drive letter thing, the file URI syntax is also more strict than the genric URI syntax, so it would be good if the standard libary could help users out on that front.

However, a relevant question is whether this should be handled by std.Uri itself or by some other external type/function defined elsewhere. Handling it in std.Uri would mean that std.Uri needs to be aware of some specific URI schemes and how their processing/validation differs from the generic URI syntax, but this is also how https://url.spec.whatwg.org/ is specified so it doesn't necessarily have to be a problem.