Address code review feedback - fix Windows test and improve validation

Co-authored-by: Byron <63622+Byron@users.noreply.github.com>

Author: Copilot

gix-url/src/simple_url.rs

@@ -21,6 +21,12 @@ pub enum ParseError {
     InvalidDomainCharacter,
 }
 
+/// Check if a character is valid in a URL scheme.
+/// Valid scheme characters: alphanumeric, +, -, or .
+fn is_valid_scheme_char(c: char) -> bool {
+    c.is_ascii_alphanumeric() || c == '+' || c == '-' || c == '.'
+}
+
 impl<'a> ParsedUrl<'a> {
     /// Parse a URL string into its components.
     /// Expected format: scheme://[user[:password]@]host[:port]/path
@@ -45,8 +51,8 @@ impl<'a> ParsedUrl<'a> {
             return Err(ParseError::RelativeUrlWithoutBase);
         }
 
-        // Validate scheme characters - schemes should only contain alphanumeric, +, -, or .
-        if !scheme.chars().all(|c| c.is_ascii_alphanumeric() || c == '+' || c == '-' || c == '.') {
+        // Validate scheme characters
+        if !scheme.chars().all(is_valid_scheme_char) {
             return Err(ParseError::RelativeUrlWithoutBase);
         }
 
@@ -138,6 +144,10 @@ impl<'a> ParsedUrl<'a> {
                 let port = potential_port
                     .parse::<u16>()
                     .map_err(|_| ParseError::InvalidPort)?;
+                // Validate port is in valid range (1-65535, port 0 is invalid)
+                if port == 0 {
+                    return Err(ParseError::InvalidPort);
+                }
                 return Ok((Some(host), Some(port)));
             }
         }

gix-url/tests/url/parse/file.rs

@@ -141,13 +141,9 @@ mod windows {
 
     #[test]
     fn url_from_absolute_path() -> crate::Result {
+        // Test with a Windows path directly instead of using url::Url::from_directory_path
         assert_url(
-            url::Url::from_directory_path(r"c:\users\1")
-                .expect("valid")
-                .to_file_path()
-                .expect("valid path")
-                .to_string_lossy()
-                .as_ref(),
+            r"C:\users\1\",
             url_alternate(Scheme::File, None, None, None, br"C:\users\1\"),
         )?;
         // A special hack to support URLs on windows that are prefixed with `/` even though absolute.