Fix validation error when a URL has credentials but no host

[karwa]

Since this branch requires that atSignSeen is true, we must have already emitted an invalid-credentials validation error and this emission must be a duplicate.

What this check is actually doing is confirming that the host is not empty before it begins parsing it, so host-missing is a more appropriate error to emit.

• [ ] At least two implementers are interested (and none opposed):
  • …
  • …
• [ ] Tests are written and can be reviewed and commented upon at:
  • …
• [ ] Implementation bugs are filed:
  • Chromium: …
  • Gecko: …
  • WebKit: …
  • Deno: …
  • Node.js: …
• [ ] MDN issue is filed: …

(See WHATWG Working Mode: Changes for more details.)

---

Preview | Diff

[karwa]

Sorry just wanted to verify it once again. I think this is correct.

[karwa]

@annevk Ah yes, okay - updated. I moved the example and replaced it with one that demonstrates credentials in a non-special scheme.