diff --git a/src/libextra/extra.rs b/src/libextra/extra.rs
index dd78ccc3a37..f4fb7bcd76c 100644
--- a/src/libextra/extra.rs
+++ b/src/libextra/extra.rs
@@ -76,6 +76,7 @@ pub mod sha2;
 
 // And ... other stuff
 
+pub mod url;
 pub mod ebml;
 pub mod dbg;
 pub mod getopts;
diff --git a/src/libextra/url.rs b/src/libextra/url.rs
new file mode 100644
index 00000000000..563619bb52d
--- /dev/null
+++ b/src/libextra/url.rs
@@ -0,0 +1,1071 @@
+// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Types/fns concerning URLs (see RFC 3986)
+
+#[allow(missing_doc)];
+
+
+use std::cmp::Eq;
+use std::io::{Reader, ReaderUtil};
+use std::io;
+use std::hashmap::HashMap;
+use std::to_bytes;
+use std::uint;
+
+#[deriving(Clone, Eq)]
+struct Url {
+    scheme: ~str,
+    user: Option<UserInfo>,
+    host: ~str,
+    port: Option<~str>,
+    path: ~str,
+    query: Query,
+    fragment: Option<~str>
+}
+
+#[deriving(Clone, Eq)]
+struct UserInfo {
+    user: ~str,
+    pass: Option<~str>
+}
+
+pub type Query = ~[(~str, ~str)];
+
+impl Url {
+    pub fn new(scheme: ~str,
+               user: Option<UserInfo>,
+               host: ~str,
+               port: Option<~str>,
+               path: ~str,
+               query: Query,
+               fragment: Option<~str>)
+               -> Url {
+        Url {
+            scheme: scheme,
+            user: user,
+            host: host,
+            port: port,
+            path: path,
+            query: query,
+            fragment: fragment,
+        }
+    }
+}
+
+impl UserInfo {
+    pub fn new(user: ~str, pass: Option<~str>) -> UserInfo {
+        UserInfo { user: user, pass: pass }
+    }
+}
+
+fn encode_inner(s: &str, full_url: bool) -> ~str {
+    do io::with_str_reader(s) |rdr| {
+        let mut out = ~"";
+
+        while !rdr.eof() {
+            let ch = rdr.read_byte() as char;
+            match ch {
+              // unreserved:
+              'A' .. 'Z' |
+              'a' .. 'z' |
+              '0' .. '9' |
+              '-' | '.' | '_' | '~' => {
+                out.push_char(ch);
+              }
+              _ => {
+                  if full_url {
+                    match ch {
+                      // gen-delims:
+                      ':' | '/' | '?' | '#' | '[' | ']' | '@' |
+
+                      // sub-delims:
+                      '!' | '$' | '&' | '"' | '(' | ')' | '*' |
+                      '+' | ',' | ';' | '=' => {
+                        out.push_char(ch);
+                      }
+
+                      _ => out.push_str(fmt!("%%%X", ch as uint))
+                    }
+                } else {
+                    out.push_str(fmt!("%%%X", ch as uint));
+                }
+              }
+            }
+        }
+
+        out
+    }
+}
+
+/**
+ * Encodes a URI by replacing reserved characters with percent encoded
+ * character sequences.
+ *
+ * This function is compliant with RFC 3986.
+ */
+pub fn encode(s: &str) -> ~str {
+    encode_inner(s, true)
+}
+
+/**
+ * Encodes a URI component by replacing reserved characters with percent
+ * encoded character sequences.
+ *
+ * This function is compliant with RFC 3986.
+ */
+
+pub fn encode_component(s: &str) -> ~str {
+    encode_inner(s, false)
+}
+
+fn decode_inner(s: &str, full_url: bool) -> ~str {
+    do io::with_str_reader(s) |rdr| {
+        let mut out = ~"";
+
+        while !rdr.eof() {
+            match rdr.read_char() {
+              '%' => {
+                let bytes = rdr.read_bytes(2u);
+                let ch = uint::parse_bytes(bytes, 16u).get() as char;
+
+                if full_url {
+                    // Only decode some characters:
+                    match ch {
+                      // gen-delims:
+                      ':' | '/' | '?' | '#' | '[' | ']' | '@' |
+
+                      // sub-delims:
+                      '!' | '$' | '&' | '"' | '(' | ')' | '*' |
+                      '+' | ',' | ';' | '=' => {
+                        out.push_char('%');
+                        out.push_char(bytes[0u] as char);
+                        out.push_char(bytes[1u] as char);
+                      }
+
+                      ch => out.push_char(ch)
+                    }
+                } else {
+                      out.push_char(ch);
+                }
+              }
+              ch => out.push_char(ch)
+            }
+        }
+
+        out
+    }
+}
+
+/**
+ * Decode a string encoded with percent encoding.
+ *
+ * This will only decode escape sequences generated by encode.
+ */
+pub fn decode(s: &str) -> ~str {
+    decode_inner(s, true)
+}
+
+/**
+ * Decode a string encoded with percent encoding.
+ */
+pub fn decode_component(s: &str) -> ~str {
+    decode_inner(s, false)
+}
+
+fn encode_plus(s: &str) -> ~str {
+    do io::with_str_reader(s) |rdr| {
+        let mut out = ~"";
+
+        while !rdr.eof() {
+            let ch = rdr.read_byte() as char;
+            match ch {
+              'A' .. 'Z' | 'a' .. 'z' | '0' .. '9' | '_' | '.' | '-' => {
+                out.push_char(ch);
+              }
+              ' ' => out.push_char('+'),
+              _ => out.push_str(fmt!("%%%X", ch as uint))
+            }
+        }
+
+        out
+    }
+}
+
+/**
+ * Encode a hashmap to the 'application/x-www-form-urlencoded' media type.
+ */
+pub fn encode_form_urlencoded(m: &HashMap<~str, ~[~str]>) -> ~str {
+    let mut out = ~"";
+    let mut first = true;
+
+    for m.iter().advance |(key, values)| {
+        let key = encode_plus(*key);
+
+        for values.iter().advance |value| {
+            if first {
+                first = false;
+            } else {
+                out.push_char('&');
+                first = false;
+            }
+
+            out.push_str(fmt!("%s=%s", key, encode_plus(*value)));
+        }
+    }
+
+    out
+}
+
+/**
+ * Decode a string encoded with the 'application/x-www-form-urlencoded' media
+ * type into a hashmap.
+ */
+pub fn decode_form_urlencoded(s: &[u8]) -> HashMap<~str, ~[~str]> {
+    do io::with_bytes_reader(s) |rdr| {
+        let mut m = HashMap::new();
+        let mut key = ~"";
+        let mut value = ~"";
+        let mut parsing_key = true;
+
+        while !rdr.eof() {
+            match rdr.read_char() {
+                '&' | ';' => {
+                    if key != ~"" && value != ~"" {
+                        let mut values = match m.pop(&key) {
+                            Some(values) => values,
+                            None => ~[],
+                        };
+
+                        values.push(value);
+                        m.insert(key, values);
+                    }
+
+                    parsing_key = true;
+                    key = ~"";
+                    value = ~"";
+                }
+                '=' => parsing_key = false,
+                ch => {
+                    let ch = match ch {
+                        '%' => {
+                            let bytes = rdr.read_bytes(2u);
+                            uint::parse_bytes(bytes, 16u).get() as char
+                        }
+                        '+' => ' ',
+                        ch => ch
+                    };
+
+                    if parsing_key {
+                        key.push_char(ch)
+                    } else {
+                        value.push_char(ch)
+                    }
+                }
+            }
+        }
+
+        if key != ~"" && value != ~"" {
+            let mut values = match m.pop(&key) {
+                Some(values) => values,
+                None => ~[],
+            };
+
+            values.push(value);
+            m.insert(key, values);
+        }
+
+        m
+    }
+}
+
+
+fn split_char_first(s: &str, c: char) -> (~str, ~str) {
+    let len = s.len();
+    let mut index = len;
+    let mut mat = 0;
+    do io::with_str_reader(s) |rdr| {
+        let mut ch;
+        while !rdr.eof() {
+            ch = rdr.read_byte() as char;
+            if ch == c {
+                // found a match, adjust markers
+                index = rdr.tell()-1;
+                mat = 1;
+                break;
+            }
+        }
+    }
+    if index+mat == len {
+        return (s.slice(0, index).to_owned(), ~"");
+    } else {
+        return (s.slice(0, index).to_owned(),
+             s.slice(index + mat, s.len()).to_owned());
+    }
+}
+
+fn userinfo_from_str(uinfo: &str) -> UserInfo {
+    let (user, p) = split_char_first(uinfo, ':');
+    let pass = if p.is_empty() {
+        None
+    } else {
+        Some(p)
+    };
+    return UserInfo::new(user, pass);
+}
+
+fn userinfo_to_str(userinfo: &UserInfo) -> ~str {
+    match userinfo.pass {
+        Some(ref pass) => fmt!("%s:%s@", userinfo.user, *pass),
+        None => fmt!("%s@", userinfo.user),
+    }
+}
+
+fn query_from_str(rawquery: &str) -> Query {
+    let mut query: Query = ~[];
+    if !rawquery.is_empty() {
+        for rawquery.split_iter('&').advance |p| {
+            let (k, v) = split_char_first(p, '=');
+            query.push((decode_component(k), decode_component(v)));
+        };
+    }
+    return query;
+}
+
+pub fn query_to_str(query: &Query) -> ~str {
+    let mut strvec = ~[];
+    for query.iter().advance |kv| {
+        match kv {
+            &(ref k, ref v) => {
+                strvec.push(fmt!("%s=%s",
+                    encode_component(*k),
+                    encode_component(*v))
+                );
+            }
+        }
+    }
+    return strvec.connect("&");
+}
+
+// returns the scheme and the rest of the url, or a parsing error
+pub fn get_scheme(rawurl: &str) -> Result<(~str, ~str), ~str> {
+    for rawurl.iter().enumerate().advance |(i,c)| {
+        match c {
+          'A' .. 'Z' | 'a' .. 'z' => loop,
+          '0' .. '9' | '+' | '-' | '.' => {
+            if i == 0 {
+                return Err(~"url: Scheme must begin with a letter.");
+            }
+            loop;
+          }
+          ':' => {
+            if i == 0 {
+                return Err(~"url: Scheme cannot be empty.");
+            } else {
+                return Ok((rawurl.slice(0,i).to_owned(),
+                                rawurl.slice(i+1,rawurl.len()).to_owned()));
+            }
+          }
+          _ => {
+            return Err(~"url: Invalid character in scheme.");
+          }
+        }
+    };
+    return Err(~"url: Scheme must be terminated with a colon.");
+}
+
+#[deriving(Clone, Eq)]
+enum Input {
+    Digit, // all digits
+    Hex, // digits and letters a-f
+    Unreserved // all other legal characters
+}
+
+// returns userinfo, host, port, and unparsed part, or an error
+fn get_authority(rawurl: &str) ->
+    Result<(Option<UserInfo>, ~str, Option<~str>, ~str), ~str> {
+    if !rawurl.starts_with("//") {
+        // there is no authority.
+        return Ok((None, ~"", None, rawurl.to_str()));
+    }
+
+    enum State {
+        Start, // starting state
+        PassHostPort, // could be in user or port
+        Ip6Port, // either in ipv6 host or port
+        Ip6Host, // are in an ipv6 host
+        InHost, // are in a host - may be ipv6, but don't know yet
+        InPort // are in port
+    }
+
+    let len = rawurl.len();
+    let mut st = Start;
+    let mut in = Digit; // most restricted, start here.
+
+    let mut userinfo = None;
+    let mut host = ~"";
+    let mut port = None;
+
+    let mut colon_count = 0;
+    let mut pos = 0;
+    let mut begin = 2;
+    let mut end = len;
+
+    for rawurl.iter().enumerate().advance |(i,c)| {
+        if i < 2 { loop; } // ignore the leading //
+
+        // deal with input class first
+        match c {
+          '0' .. '9' => (),
+          'A' .. 'F' | 'a' .. 'f' => {
+            if in == Digit {
+                in = Hex;
+            }
+          }
+          'G' .. 'Z' | 'g' .. 'z' | '-' | '.' | '_' | '~' | '%' |
+          '&' |'\'' | '(' | ')' | '+' | '!' | '*' | ',' | ';' | '=' => {
+            in = Unreserved;
+          }
+          ':' | '@' | '?' | '#' | '/' => {
+            // separators, don't change anything
+          }
+          _ => {
+            return Err(~"Illegal character in authority");
+          }
+        }
+
+        // now process states
+        match c {
+          ':' => {
+            colon_count += 1;
+            match st {
+              Start => {
+                pos = i;
+                st = PassHostPort;
+              }
+              PassHostPort => {
+                // multiple colons means ipv6 address.
+                if in == Unreserved {
+                    return Err(
+                        ~"Illegal characters in IPv6 address.");
+                }
+                st = Ip6Host;
+              }
+              InHost => {
+                pos = i;
+                // can't be sure whether this is an ipv6 address or a port
+                if in == Unreserved {
+                    return Err(~"Illegal characters in authority.");
+                }
+                st = Ip6Port;
+              }
+              Ip6Port => {
+                if in == Unreserved {
+                    return Err(~"Illegal characters in authority.");
+                }
+                st = Ip6Host;
+              }
+              Ip6Host => {
+                if colon_count > 7 {
+                    host = rawurl.slice(begin, i).to_owned();
+                    pos = i;
+                    st = InPort;
+                }
+              }
+              _ => {
+                return Err(~"Invalid ':' in authority.");
+              }
+            }
+            in = Digit; // reset input class
+          }
+
+          '@' => {
+            in = Digit; // reset input class
+            colon_count = 0; // reset count
+            match st {
+              Start => {
+                let user = rawurl.slice(begin, i).to_owned();
+                userinfo = Some(UserInfo::new(user, None));
+                st = InHost;
+              }
+              PassHostPort => {
+                let user = rawurl.slice(begin, pos).to_owned();
+                let pass = rawurl.slice(pos+1, i).to_owned();
+                userinfo = Some(UserInfo::new(user, Some(pass)));
+                st = InHost;
+              }
+              _ => {
+                return Err(~"Invalid '@' in authority.");
+              }
+            }
+            begin = i+1;
+          }
+
+          '?' | '#' | '/' => {
+            end = i;
+            break;
+          }
+          _ => ()
+        }
+        end = i;
+    }
+
+    let end = end; // make end immutable so it can be captured
+
+    let host_is_end_plus_one: &fn() -> bool = || {
+        let xs = ['?', '#', '/'];
+        end+1 == len
+            && !xs.iter().any(|x| *x == (rawurl[end] as char))
+    };
+
+    // finish up
+    match st {
+      Start => {
+        if host_is_end_plus_one() {
+            host = rawurl.slice(begin, end+1).to_owned();
+        } else {
+            host = rawurl.slice(begin, end).to_owned();
+        }
+      }
+      PassHostPort | Ip6Port => {
+        if in != Digit {
+            return Err(~"Non-digit characters in port.");
+        }
+        host = rawurl.slice(begin, pos).to_owned();
+        port = Some(rawurl.slice(pos+1, end).to_owned());
+      }
+      Ip6Host | InHost => {
+        host = rawurl.slice(begin, end).to_owned();
+      }
+      InPort => {
+        if in != Digit {
+            return Err(~"Non-digit characters in port.");
+        }
+        port = Some(rawurl.slice(pos+1, end).to_owned());
+      }
+    }
+
+    let rest = if host_is_end_plus_one() { ~"" }
+    else { rawurl.slice(end, len).to_owned() };
+    return Ok((userinfo, host, port, rest));
+}
+
+
+// returns the path and unparsed part of url, or an error
+fn get_path(rawurl: &str, authority: bool) ->
+    Result<(~str, ~str), ~str> {
+    let len = rawurl.len();
+    let mut end = len;
+    for rawurl.iter().enumerate().advance |(i,c)| {
+        match c {
+          'A' .. 'Z' | 'a' .. 'z' | '0' .. '9' | '&' |'\'' | '(' | ')' | '.'
+          | '@' | ':' | '%' | '/' | '+' | '!' | '*' | ',' | ';' | '='
+          | '_' | '-' => {
+            loop;
+          }
+          '?' | '#' => {
+            end = i;
+            break;
+          }
+          _ => return Err(~"Invalid character in path.")
+        }
+    }
+
+    if authority {
+        if end != 0 && !rawurl.starts_with("/") {
+            return Err(~"Non-empty path must begin with\
+                               '/' in presence of authority.");
+        }
+    }
+
+    return Ok((decode_component(rawurl.slice(0, end)),
+                    rawurl.slice(end, len).to_owned()));
+}
+
+// returns the parsed query and the fragment, if present
+fn get_query_fragment(rawurl: &str) ->
+    Result<(Query, Option<~str>), ~str> {
+    if !rawurl.starts_with("?") {
+        if rawurl.starts_with("#") {
+            let f = decode_component(rawurl.slice(
+                                                1,
+                                                rawurl.len()));
+            return Ok((~[], Some(f)));
+        } else {
+            return Ok((~[], None));
+        }
+    }
+    let (q, r) = split_char_first(rawurl.slice(1, rawurl.len()), '#');
+    let f = if r.len() != 0 {
+        Some(decode_component(r)) } else { None };
+    return Ok((query_from_str(q), f));
+}
+
+/**
+ * Parse a `str` to a `url`
+ *
+ * # Arguments
+ *
+ * `rawurl` - a string representing a full url, including scheme.
+ *
+ * # Returns
+ *
+ * a `url` that contains the parsed representation of the url.
+ *
+ */
+
+pub fn from_str(rawurl: &str) -> Result<Url, ~str> {
+    // scheme
+    let (scheme, rest) = match get_scheme(rawurl) {
+        Ok(val) => val,
+        Err(e) => return Err(e),
+    };
+
+    // authority
+    let (userinfo, host, port, rest) = match get_authority(rest) {
+        Ok(val) => val,
+        Err(e) => return Err(e),
+    };
+
+    // path
+    let has_authority = if host == ~"" { false } else { true };
+    let (path, rest) = match get_path(rest, has_authority) {
+        Ok(val) => val,
+        Err(e) => return Err(e),
+    };
+
+    // query and fragment
+    let (query, fragment) = match get_query_fragment(rest) {
+        Ok(val) => val,
+        Err(e) => return Err(e),
+    };
+
+    Ok(Url::new(scheme, userinfo, host, port, path, query, fragment))
+}
+
+impl FromStr for Url {
+    fn from_str(s: &str) -> Option<Url> {
+        match from_str(s) {
+            Ok(url) => Some(url),
+            Err(_) => None
+        }
+    }
+}
+
+/**
+ * Format a `url` as a string
+ *
+ * # Arguments
+ *
+ * `url` - a url.
+ *
+ * # Returns
+ *
+ * a `str` that contains the formatted url. Note that this will usually
+ * be an inverse of `from_str` but might strip out unneeded separators.
+ * for example, "http://somehost.com?", when parsed and formatted, will
+ * result in just "http://somehost.com".
+ *
+ */
+pub fn to_str(url: &Url) -> ~str {
+    let user = match url.user {
+        Some(ref user) => userinfo_to_str(user),
+        None => ~"",
+    };
+
+    let authority = if url.host.is_empty() {
+        ~""
+    } else {
+        fmt!("//%s%s", user, url.host)
+    };
+
+    let query = if url.query.is_empty() {
+        ~""
+    } else {
+        fmt!("?%s", query_to_str(&url.query))
+    };
+
+    let fragment = match url.fragment {
+        Some(ref fragment) => fmt!("#%s", encode_component(*fragment)),
+        None => ~"",
+    };
+
+    fmt!("%s:%s%s%s%s", url.scheme, authority, url.path, query, fragment)
+}
+
+impl ToStr for Url {
+    pub fn to_str(&self) -> ~str {
+        to_str(self)
+    }
+}
+
+impl IterBytes for Url {
+    fn iter_bytes(&self, lsb0: bool, f: to_bytes::Cb) -> bool {
+        self.to_str().iter_bytes(lsb0, f)
+    }
+}
+
+// Put a few tests outside of the 'test' module so they can test the internal
+// functions and those functions don't need 'pub'
+
+#[test]
+fn test_split_char_first() {
+    let (u,v) = split_char_first("hello, sweet world", ',');
+    assert_eq!(u, ~"hello");
+    assert_eq!(v, ~" sweet world");
+
+    let (u,v) = split_char_first("hello sweet world", ',');
+    assert_eq!(u, ~"hello sweet world");
+    assert_eq!(v, ~"");
+}
+
+#[test]
+fn test_get_authority() {
+    let (u, h, p, r) = get_authority(
+        "//user:pass@rust-lang.org/something").unwrap();
+    assert_eq!(u, Some(UserInfo::new(~"user", Some(~"pass"))));
+    assert_eq!(h, ~"rust-lang.org");
+    assert!(p.is_none());
+    assert_eq!(r, ~"/something");
+
+    let (u, h, p, r) = get_authority(
+        "//rust-lang.org:8000?something").unwrap();
+    assert!(u.is_none());
+    assert_eq!(h, ~"rust-lang.org");
+    assert_eq!(p, Some(~"8000"));
+    assert_eq!(r, ~"?something");
+
+    let (u, h, p, r) = get_authority(
+        "//rust-lang.org#blah").unwrap();
+    assert!(u.is_none());
+    assert_eq!(h, ~"rust-lang.org");
+    assert!(p.is_none());
+    assert_eq!(r, ~"#blah");
+
+    // ipv6 tests
+    let (_, h, _, _) = get_authority(
+        "//2001:0db8:85a3:0042:0000:8a2e:0370:7334#blah").unwrap();
+    assert_eq!(h, ~"2001:0db8:85a3:0042:0000:8a2e:0370:7334");
+
+    let (_, h, p, _) = get_authority(
+        "//2001:0db8:85a3:0042:0000:8a2e:0370:7334:8000#blah").unwrap();
+    assert_eq!(h, ~"2001:0db8:85a3:0042:0000:8a2e:0370:7334");
+    assert_eq!(p, Some(~"8000"));
+
+    let (u, h, p, _) = get_authority(
+        "//us:p@2001:0db8:85a3:0042:0000:8a2e:0370:7334:8000#blah"
+    ).unwrap();
+    assert_eq!(u, Some(UserInfo::new(~"us", Some(~"p"))));
+    assert_eq!(h, ~"2001:0db8:85a3:0042:0000:8a2e:0370:7334");
+    assert_eq!(p, Some(~"8000"));
+
+    // invalid authorities;
+    assert!(get_authority("//user:pass@rust-lang:something").is_err());
+    assert!(get_authority("//user@rust-lang:something:/path").is_err());
+    assert!(get_authority(
+        "//2001:0db8:85a3:0042:0000:8a2e:0370:7334:800a").is_err());
+    assert!(get_authority(
+        "//2001:0db8:85a3:0042:0000:8a2e:0370:7334:8000:00").is_err());
+
+    // these parse as empty, because they don't start with '//'
+    let (_, h, _, _) = get_authority("user:pass@rust-lang").unwrap();
+    assert_eq!(h, ~"");
+    let (_, h, _, _) = get_authority("rust-lang.org").unwrap();
+    assert_eq!(h, ~"");
+}
+
+#[test]
+fn test_get_path() {
+    let (p, r) = get_path("/something+%20orother", true).unwrap();
+    assert_eq!(p, ~"/something+ orother");
+    assert_eq!(r, ~"");
+    let (p, r) = get_path("test@email.com#fragment", false).unwrap();
+    assert_eq!(p, ~"test@email.com");
+    assert_eq!(r, ~"#fragment");
+    let (p, r) = get_path("/gen/:addr=?q=v", false).unwrap();
+    assert_eq!(p, ~"/gen/:addr=");
+    assert_eq!(r, ~"?q=v");
+
+    //failure cases
+    assert!(get_path("something?q", true).is_err());
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+
+    use std::hashmap::HashMap;
+
+    #[test]
+    fn test_url_parse() {
+        let url = ~"http://user:pass@rust-lang.org/doc?s=v#something";
+
+        let up = from_str(url);
+        let u = up.unwrap();
+        assert!(u.scheme == ~"http");
+        let userinfo = u.user.get_ref();
+        assert!(userinfo.user == ~"user");
+        assert!(userinfo.pass.get_ref() == &~"pass");
+        assert!(u.host == ~"rust-lang.org");
+        assert!(u.path == ~"/doc");
+        assert!(u.query == ~[(~"s", ~"v")]);
+        assert!(u.fragment.get_ref() == &~"something");
+    }
+
+    #[test]
+    fn test_url_parse_host_slash() {
+        let urlstr = ~"http://0.42.42.42/";
+        let url = from_str(urlstr).unwrap();
+        assert!(url.host == ~"0.42.42.42");
+        assert!(url.path == ~"/");
+    }
+
+    #[test]
+    fn test_url_with_underscores() {
+        let urlstr = ~"http://dotcom.com/file_name.html";
+        let url = from_str(urlstr).unwrap();
+        assert!(url.path == ~"/file_name.html");
+    }
+
+    #[test]
+    fn test_url_with_dashes() {
+        let urlstr = ~"http://dotcom.com/file-name.html";
+        let url = from_str(urlstr).unwrap();
+        assert!(url.path == ~"/file-name.html");
+    }
+
+    #[test]
+    fn test_no_scheme() {
+        assert!(get_scheme("noschemehere.html").is_err());
+    }
+
+    #[test]
+    fn test_invalid_scheme_errors() {
+        assert!(from_str("99://something").is_err());
+        assert!(from_str("://something").is_err());
+    }
+
+    #[test]
+    fn test_full_url_parse_and_format() {
+        let url = ~"http://user:pass@rust-lang.org/doc?s=v#something";
+        assert_eq!(from_str(url).unwrap().to_str(), url);
+    }
+
+    #[test]
+    fn test_userless_url_parse_and_format() {
+        let url = ~"http://rust-lang.org/doc?s=v#something";
+        assert_eq!(from_str(url).unwrap().to_str(), url);
+    }
+
+    #[test]
+    fn test_queryless_url_parse_and_format() {
+        let url = ~"http://user:pass@rust-lang.org/doc#something";
+        assert_eq!(from_str(url).unwrap().to_str(), url);
+    }
+
+    #[test]
+    fn test_empty_query_url_parse_and_format() {
+        let url = ~"http://user:pass@rust-lang.org/doc?#something";
+        let should_be = ~"http://user:pass@rust-lang.org/doc#something";
+        assert_eq!(from_str(url).unwrap().to_str(), should_be);
+    }
+
+    #[test]
+    fn test_fragmentless_url_parse_and_format() {
+        let url = ~"http://user:pass@rust-lang.org/doc?q=v";
+        assert_eq!(from_str(url).unwrap().to_str(), url);
+    }
+
+    #[test]
+    fn test_minimal_url_parse_and_format() {
+        let url = ~"http://rust-lang.org/doc";
+        assert_eq!(from_str(url).unwrap().to_str(), url);
+    }
+
+    #[test]
+    fn test_scheme_host_only_url_parse_and_format() {
+        let url = ~"http://rust-lang.org";
+        assert_eq!(from_str(url).unwrap().to_str(), url);
+    }
+
+    #[test]
+    fn test_pathless_url_parse_and_format() {
+        let url = ~"http://user:pass@rust-lang.org?q=v#something";
+        assert_eq!(from_str(url).unwrap().to_str(), url);
+    }
+
+    #[test]
+    fn test_scheme_host_fragment_only_url_parse_and_format() {
+        let url = ~"http://rust-lang.org#something";
+        assert_eq!(from_str(url).unwrap().to_str(), url);
+    }
+
+    #[test]
+    fn test_url_component_encoding() {
+        let url = ~"http://rust-lang.org/doc%20uments?ba%25d%20=%23%26%2B";
+        let u = from_str(url).unwrap();
+        assert!(u.path == ~"/doc uments");
+        assert!(u.query == ~[(~"ba%d ", ~"#&+")]);
+    }
+
+    #[test]
+    fn test_url_without_authority() {
+        let url = ~"mailto:test@email.com";
+        assert_eq!(from_str(url).unwrap().to_str(), url);
+    }
+
+    #[test]
+    fn test_encode() {
+        assert_eq!(encode(""), ~"");
+        assert_eq!(encode("http://example.com"), ~"http://example.com");
+        assert_eq!(encode("foo bar% baz"), ~"foo%20bar%25%20baz");
+        assert_eq!(encode(" "), ~"%20");
+        assert_eq!(encode("!"), ~"!");
+        assert_eq!(encode("\""), ~"\"");
+        assert_eq!(encode("#"), ~"#");
+        assert_eq!(encode("$"), ~"$");
+        assert_eq!(encode("%"), ~"%25");
+        assert_eq!(encode("&"), ~"&");
+        assert_eq!(encode("'"), ~"%27");
+        assert_eq!(encode("("), ~"(");
+        assert_eq!(encode(")"), ~")");
+        assert_eq!(encode("*"), ~"*");
+        assert_eq!(encode("+"), ~"+");
+        assert_eq!(encode(","), ~",");
+        assert_eq!(encode("/"), ~"/");
+        assert_eq!(encode(":"), ~":");
+        assert_eq!(encode(";"), ~";");
+        assert_eq!(encode("="), ~"=");
+        assert_eq!(encode("?"), ~"?");
+        assert_eq!(encode("@"), ~"@");
+        assert_eq!(encode("["), ~"[");
+        assert_eq!(encode("]"), ~"]");
+    }
+
+    #[test]
+    fn test_encode_component() {
+        assert_eq!(encode_component(""), ~"");
+        assert!(encode_component("http://example.com") ==
+            ~"http%3A%2F%2Fexample.com");
+        assert!(encode_component("foo bar% baz") ==
+            ~"foo%20bar%25%20baz");
+        assert_eq!(encode_component(" "), ~"%20");
+        assert_eq!(encode_component("!"), ~"%21");
+        assert_eq!(encode_component("#"), ~"%23");
+        assert_eq!(encode_component("$"), ~"%24");
+        assert_eq!(encode_component("%"), ~"%25");
+        assert_eq!(encode_component("&"), ~"%26");
+        assert_eq!(encode_component("'"), ~"%27");
+        assert_eq!(encode_component("("), ~"%28");
+        assert_eq!(encode_component(")"), ~"%29");
+        assert_eq!(encode_component("*"), ~"%2A");
+        assert_eq!(encode_component("+"), ~"%2B");
+        assert_eq!(encode_component(","), ~"%2C");
+        assert_eq!(encode_component("/"), ~"%2F");
+        assert_eq!(encode_component(":"), ~"%3A");
+        assert_eq!(encode_component(";"), ~"%3B");
+        assert_eq!(encode_component("="), ~"%3D");
+        assert_eq!(encode_component("?"), ~"%3F");
+        assert_eq!(encode_component("@"), ~"%40");
+        assert_eq!(encode_component("["), ~"%5B");
+        assert_eq!(encode_component("]"), ~"%5D");
+    }
+
+    #[test]
+    fn test_decode() {
+        assert_eq!(decode(""), ~"");
+        assert_eq!(decode("abc/def 123"), ~"abc/def 123");
+        assert_eq!(decode("abc%2Fdef%20123"), ~"abc%2Fdef 123");
+        assert_eq!(decode("%20"), ~" ");
+        assert_eq!(decode("%21"), ~"%21");
+        assert_eq!(decode("%22"), ~"%22");
+        assert_eq!(decode("%23"), ~"%23");
+        assert_eq!(decode("%24"), ~"%24");
+        assert_eq!(decode("%25"), ~"%");
+        assert_eq!(decode("%26"), ~"%26");
+        assert_eq!(decode("%27"), ~"'");
+        assert_eq!(decode("%28"), ~"%28");
+        assert_eq!(decode("%29"), ~"%29");
+        assert_eq!(decode("%2A"), ~"%2A");
+        assert_eq!(decode("%2B"), ~"%2B");
+        assert_eq!(decode("%2C"), ~"%2C");
+        assert_eq!(decode("%2F"), ~"%2F");
+        assert_eq!(decode("%3A"), ~"%3A");
+        assert_eq!(decode("%3B"), ~"%3B");
+        assert_eq!(decode("%3D"), ~"%3D");
+        assert_eq!(decode("%3F"), ~"%3F");
+        assert_eq!(decode("%40"), ~"%40");
+        assert_eq!(decode("%5B"), ~"%5B");
+        assert_eq!(decode("%5D"), ~"%5D");
+    }
+
+    #[test]
+    fn test_decode_component() {
+        assert_eq!(decode_component(""), ~"");
+        assert_eq!(decode_component("abc/def 123"), ~"abc/def 123");
+        assert_eq!(decode_component("abc%2Fdef%20123"), ~"abc/def 123");
+        assert_eq!(decode_component("%20"), ~" ");
+        assert_eq!(decode_component("%21"), ~"!");
+        assert_eq!(decode_component("%22"), ~"\"");
+        assert_eq!(decode_component("%23"), ~"#");
+        assert_eq!(decode_component("%24"), ~"$");
+        assert_eq!(decode_component("%25"), ~"%");
+        assert_eq!(decode_component("%26"), ~"&");
+        assert_eq!(decode_component("%27"), ~"'");
+        assert_eq!(decode_component("%28"), ~"(");
+        assert_eq!(decode_component("%29"), ~")");
+        assert_eq!(decode_component("%2A"), ~"*");
+        assert_eq!(decode_component("%2B"), ~"+");
+        assert_eq!(decode_component("%2C"), ~",");
+        assert_eq!(decode_component("%2F"), ~"/");
+        assert_eq!(decode_component("%3A"), ~":");
+        assert_eq!(decode_component("%3B"), ~";");
+        assert_eq!(decode_component("%3D"), ~"=");
+        assert_eq!(decode_component("%3F"), ~"?");
+        assert_eq!(decode_component("%40"), ~"@");
+        assert_eq!(decode_component("%5B"), ~"[");
+        assert_eq!(decode_component("%5D"), ~"]");
+    }
+
+    #[test]
+    fn test_encode_form_urlencoded() {
+        let mut m = HashMap::new();
+        assert_eq!(encode_form_urlencoded(&m), ~"");
+
+        m.insert(~"", ~[]);
+        m.insert(~"foo", ~[]);
+        assert_eq!(encode_form_urlencoded(&m), ~"");
+
+        let mut m = HashMap::new();
+        m.insert(~"foo", ~[~"bar", ~"123"]);
+        assert_eq!(encode_form_urlencoded(&m), ~"foo=bar&foo=123");
+
+        let mut m = HashMap::new();
+        m.insert(~"foo bar", ~[~"abc", ~"12 = 34"]);
+        assert!(encode_form_urlencoded(&m) ==
+            ~"foo+bar=abc&foo+bar=12+%3D+34");
+    }
+
+    #[test]
+    fn test_decode_form_urlencoded() {
+        // FIXME #4449: Commented out because this causes an ICE, but only
+        // on FreeBSD
+        /*
+        assert_eq!(decode_form_urlencoded([]).len(), 0);
+
+        let s = "a=1&foo+bar=abc&foo+bar=12+%3D+34".as_bytes();
+        let form = decode_form_urlencoded(s);
+        assert_eq!(form.len(), 2);
+        assert_eq!(form.get_ref(&~"a"), &~[~"1"]);
+        assert_eq!(form.get_ref(&~"foo bar"), &~[~"abc", ~"12 = 34"]);
+        */
+    }
+}