update url polyfill to handle hostless URLs

Author: guybedford

src/url-polyfill.js

@@ -4,9 +4,8 @@ function URLPolyfill(url, baseURL) {
   if (typeof url != 'string')
     throw new TypeError('URL must be a string');
   var m = String(url).replace(/^\s+|\s+$/g, "").match(/^([^:\/?#]+:)?(?:\/\/(?:([^:@\/?#]*)(?::([^:@\/?#]*))?@)?(([^:\/?#]*)(?::(\d*))?))?([^?#]*)(\?[^#]*)?(#[\s\S]*)?/);
-  if (!m) {
-    throw new RangeError();
-  }
+  if (!m)
+    throw new RangeError('Invalid URL format');
   var protocol = m[1] || "";
   var username = m[2] || "";
   var password = m[3] || "";
@@ -18,44 +17,40 @@ function URLPolyfill(url, baseURL) {
   var hash = m[9] || "";
   if (baseURL !== undefined) {
     var base = baseURL instanceof URLPolyfill ? baseURL : new URLPolyfill(baseURL);
-    var flag = protocol === "" && host === "" && username === "";
-    if (flag && pathname === "" && search === "") {
+    var flag = !protocol && !host && !username;
+    if (flag && !pathname && !search)
       search = base.search;
-    }
-    if (flag && pathname.charAt(0) !== "/") {
-      pathname = (pathname !== "" ? (((base.host !== "" || base.username !== "") && base.pathname === "" ? "/" : "") + base.pathname.slice(0, base.pathname.lastIndexOf("/") + 1) + pathname) : base.pathname);
-    }
+    if (flag && pathname[0] !== "/")
+      pathname = (pathname ? (((base.host || base.username) && !base.pathname ? "/" : "") + base.pathname.slice(0, base.pathname.lastIndexOf("/") + 1) + pathname) : base.pathname);
     // dot segments removal
     var output = [];
     pathname.replace(/^(\.\.?(\/|$))+/, "")
       .replace(/\/(\.(\/|$))+/g, "/")
       .replace(/\/\.\.$/, "/../")
       .replace(/\/?[^\/]*/g, function (p) {
-        if (p === "/..") {
+        if (p === "/..")
           output.pop();
-        } else {
+        else
           output.push(p);
-        }
       });
-    pathname = output.join("").replace(/^\//, pathname.charAt(0) === "/" ? "/" : "");
+    pathname = output.join("").replace(/^\//, pathname[0] === "/" ? "/" : "");
     if (flag) {
       port = base.port;
       hostname = base.hostname;
       host = base.host;
       password = base.password;
       username = base.username;
     }
-    if (protocol === "") {
+    if (!protocol)
       protocol = base.protocol;
-    }
   }
 
   // convert windows file URLs to use /
   if (protocol == 'file:')
     pathname = pathname.replace(/\\/g, '/');
 
-  this.origin = protocol + (protocol !== "" || host !== "" ? "//" : "") + host;
-  this.href = protocol + (protocol !== "" || host !== "" ? "//" : "") + (username !== "" ? username + (password !== "" ? ":" + password : "") + "@" : "") + host + pathname + search + hash;
+  this.origin = host ? protocol + (protocol !== "" || host !== "" ? "//" : "") + host : "";
+  this.href = protocol + (protocol && host || protocol == "file:" ? "//" : "") + (username !== "" ? username + (password !== "" ? ":" + password : "") + "@" : "") + host + pathname + search + hash;
   this.protocol = protocol;
   this.username = username;
   this.password = password;