Fix invalid URIs generated using Uri constructor with clever paths.

sdk/lib/core/uri.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.core;
 
 // Frequently used character codes.
 const int _SPACE = 0x20;
 const int _PERCENT = 0x25;
 const int _PLUS = 0x2B;
@@ skipping 361 matching lines @@
    *
    * The host string is case-insensitive.
    * The returned host name is canonicalized to lower-case
    * with upper-case percent-escapes.
    */
   String get host;
 
   /**
    * Returns the port part of the authority component.
    *
-   * Returns the defualt port if there is no port number in the authority
+   * Returns the default port if there is no port number in the authority
    * component. That's 80 for http, 443 for https, and 0 for everything else.
    */
   int get port;
 
   /**
    * Returns the path component.
    *
    * The returned path is encoded. To get direct access to the decoded
    * path use [pathSegments].
    *
@@ skipping 105 matching lines @@
 
   /**
    * Returns whether the URI has an absolute path (starting with '/').
    */
   bool get hasAbsolutePath;
 
   /**
    * Returns the origin of the URI in the form scheme://host:port for the
    * schemes http and https.
    *
-   * It is an error if the scheme is not "http" or "https".
+   * It is an error if the scheme is not "http" or "https", or if the host name
+   * is missing or empty.
    *
    * See: http://www.w3.org/TR/2011/WD-html5-20110405/origin-0.html#origin
    */
   String get origin;
 
   /**
    * Returns the file path from a file URI.
    *
    * The returned path has either Windows or non-Windows
    * semantics.
@@ skipping 944 matching lines @@
     port = _makePort(port, scheme);
     bool isFile = (scheme == "file");
     if (host == null &&
         (userInfo.isNotEmpty || port != null || isFile)) {
       host = "";
     }
     bool hasAuthority = (host != null);
     path = _makePath(path, 0, _stringOrNullLength(path), pathSegments,
                      scheme, hasAuthority);
     if (scheme.isEmpty && host == null && !path.startsWith('/')) {
-      path = _normalizeRelativePath(path, scheme.isNotEmpty || host != null);
+      bool allowScheme = scheme.isNotEmpty || host != null;
+      path = _normalizeRelativePath(path, allowScheme);
     } else {
       path = _removeDotSegments(path);
     }
     if (host == null && path.startsWith("//")) {
       host = "";
     }
     return new _Uri._internal(scheme, userInfo, host, port,
                               path, query, fragment);
   }
 
@@ skipping 1029 matching lines @@
 
   bool get hasQuery => _query != null;
 
   bool get hasFragment => _fragment != null;
 
   bool get hasEmptyPath => _path.isEmpty;
 
   bool get hasAbsolutePath => _path.startsWith('/');
 
   String get origin {
-    if (scheme == "" || _host == null || _host == "") {
+    if (scheme == "") {
       throw new StateError("Cannot use origin without a scheme: $this");
     }
     if (scheme != "http" && scheme != "https") {
       throw new StateError(
         "Origin is only applicable schemes http and https: $this");
     }
+    if (_host == null || _host == "") {
+      throw new StateError(
+          "A $scheme: URI should have a non-empty host name: $this");
+    }
     if (_port == null) return "$scheme://$_host";
     return "$scheme://$_host:$_port";
   }
 
   String toFilePath({bool windows}) {
     if (scheme != "" && scheme != "file") {
       throw new UnsupportedError(
           "Cannot extract a file path from a $scheme URI");
     }
     if (query != "") {
@@ skipping 1563 matching lines @@
   }
   String get path =>_uri.substring(_pathStart, _queryStart);
   String get query => (_queryStart < _fragmentStart) ?
      _uri.substring(_queryStart + 1, _fragmentStart) : "";
   String get fragment => (_fragmentStart < _uri.length) ?
      _uri.substring(_fragmentStart + 1) : "";
 
   String get origin {
     // Check original behavior - W3C spec is wonky!
     bool isHttp = _isHttp;
-    if (_schemeEnd < 0 || _hostStart == _portStart) {
+    if (_schemeEnd < 0) {
       throw new StateError("Cannot use origin without a scheme: $this");
     }
     if (!isHttp && !_isHttps) {
       throw new StateError(
         "Origin is only applicable schemes http and https: $this");
     }
+    if (_hostStart == _portStart) {
+      throw new StateError(
+          "A $scheme: URI should have a non-empty host name: $this");
+    }
     if (_hostStart == _schemeEnd + 3) {
       return _uri.substring(0, _pathStart);
     }
     // Need to drop anon-empty userInfo.
     return _uri.substring(0, _schemeEnd + 3) +
            _uri.substring(_hostStart, _pathStart);
   }
 
   List<String> get pathSegments {
     int start = _pathStart;
@@ skipping 366 matching lines @@
   int delta = (text.codeUnitAt(start + 4) ^ _COLON) * 3;
   delta |= text.codeUnitAt(start)     ^ 0x64 /*d*/;
   delta |= text.codeUnitAt(start + 1) ^ 0x61 /*a*/;
   delta |= text.codeUnitAt(start + 2) ^ 0x74 /*t*/;
   delta |= text.codeUnitAt(start + 3) ^ 0x61 /*a*/;
   return delta;
 }
 
 /// Helper function returning the length of a string, or `0` for `null`.
 int _stringOrNullLength(String s) => (s == null) ? 0 : s.length;