30 tests to go.

Author: o0Ignition0o

src/parser.rs

@@ -894,6 +894,14 @@ impl<'a> Parser<'a> {
         let (host, remaining) = Parser::parse_host(input, scheme_type)?;
         write!(&mut self.serialization, "{}", host).unwrap();
         let host_end = to_u32(self.serialization.len())?;
+        if remaining.starts_with(":") {
+            // Port with an empty host
+            if let Host::Domain(h) = &host {
+                if h.is_empty() {
+                    return Err(ParseError::EmptyHost);
+                }
+            }
+        }
         let (port, remaining) = if let Some(remaining) = remaining.split_prefix(':') {
             let scheme = || default_port(&self.serialization[..scheme_end as usize]);
             Parser::parse_port(remaining, scheme, self.context)?

src/quirks.rs

@@ -157,6 +157,20 @@ pub fn set_hostname(url: &mut Url, new_hostname: &str) -> Result<(), ()> {
     }
     let result = Parser::parse_host(Input::new(new_hostname), SchemeType::from(url.scheme()));
     if let Ok((host, _remaining)) = result {
+        if let Host::Domain(h) = &host {
+            if h.is_empty() {
+                // Empty host on special url
+                if SchemeType::from(url.scheme()).is_special()
+                    // Port with an empty host
+                    ||!port(&url).is_empty()
+                    // Empty host with includes credentials
+                    || !url.username().is_empty()
+                    || !url.password().unwrap_or(&"").is_empty()
+                {
+                    return Err(());
+                }
+            }
+        }
         url.set_host_internal(host, None);
         Ok(())
     } else {
@@ -201,7 +215,7 @@ pub fn pathname(url: &Url) -> &str {
 
 /// Setter for https://url.spec.whatwg.org/#dom-url-pathname
 pub fn set_pathname(url: &mut Url, new_pathname: &str) {
-    if !url.cannot_be_a_base() {
+    if url.cannot_be_a_base() {
         return;
     }
     if !SchemeType::from(url.scheme()).is_special()