uri_reference.is_valid() accepts invalid hostnames and out-of-range ports

[QuantumNovice]

The validator returns True for inputs that violate URI rules.

Examples:

In [15]:  uri_reference('google.com/path').is_valid()
Out[15]: True

In [27]:  uri_reference('http://example.com:99999/').is_valid()
Out[27]: True

Expected behavior:

The validator should reject missing schemes when a hostname is present
and should reject port values greater than 65535.

Actual behavior:

is_valid() returns True for both invalid inputs.

Steps to reproduce:

1. Run the two example expressions in a Python REPL.
2. Observe that both return True.

Environment:

Library version:
Python version: Python 3.10.14
OS: Windows

Fix? :

• Add port range validation and treat bare hostnames with paths as invalid
• unless explicitly allowed by the spec.

[woodruffw]

Note that RFC 3986 doesn't impose a limit on port numbers: from 3.2.3:

  port        = *DIGIT

and from the top-level grammar:

   authority     = [ userinfo "@" ] host [ ":" port ]
   userinfo      = *( unreserved / pct-encoded / sub-delims / ":" )
   host          = IP-literal / IPv4address / reg-name
   port          = *DIGIT

(Curiously, this also permits an empty port, so https://google.com:/path is a valid URI according to RFC3986.)