Allow multiple dirs per package in the data returned by "pub list".

pkg/analysis_server/lib/src/package_uri_resolver.dart

 // Copyright (c) 2014, 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.
 
 library resolver.package;
 
 import 'package:analysis_server/src/resource.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 
 
 /**
  * A [UriResolver] implementation for the `package:` scheme that uses a map of
  * package names to their directories.
  */
 class PackageMapUriResolver extends UriResolver {
   /**
    * The name of the `package` scheme.
    */
   static const String PACKAGE_SCHEME = "package";
 
   /**
-   * A table mapping package names to the path of the directory containing
+   * A table mapping package names to the path of the directories containing
    * the package.
    */
-  final Map<String, Folder> packageMap;
+  final Map<String, List<Folder>> packageMap;
 
   /**
    * The [ResourceProvider] for this resolver.
    */
   final ResourceProvider resourceProvider;
 
   /**
    * Create a new [PackageMapUriResolver].
    *
-   * [packageMap] is a table mapping package names to the path of the directory
-   * containing the package
+   * [packageMap] is a table mapping package names to the paths of the
+   * directories containing the package
    */
   PackageMapUriResolver(this.resourceProvider, this.packageMap);
 
   @override
   Source fromEncoding(UriKind kind, Uri uri) {
     if (kind == UriKind.PACKAGE_URI) {
       Resource resource = resourceProvider.getResource(uri.path);
       if (resource is File) {
         return resource.createSource(kind);
       }
@@ skipping 13 matching lines @@
     String relPath;
     int index = path.indexOf('/');
     if (index == -1 || index == 0) {
       return null;
     } else {
       // <pkgName>/<relPath>
       pkgName = path.substring(0, index);
       relPath = path.substring(index + 1);
     }
     // Try to find an existing file.
-    Folder packageDir = packageMap[pkgName];
-    if (packageDir != null && packageDir.exists) {
-      Resource result = packageDir.getChild(relPath);
-      if (result is File && result.exists) {
-        return result.createSource(UriKind.PACKAGE_URI);
+    List<Folder> packageDirs = packageMap[pkgName];
+    if (packageDirs != null) {
+      for (Folder packageDir in packageDirs) {
+        if (packageDir.exists) {
+          Resource result = packageDir.getChild(relPath);
+          if (result is File && result.exists) {
+            return result.createSource(UriKind.PACKAGE_URI);
+          }
+        }
       }
     }
     // Return a NonExistingSource instance.
     // This helps provide more meaningful error messages to users
     // (a missing file error, as opposed to an invalid URI error).
     // TODO(scheglov) move NonExistingSource to "source.dart"
     return new NonExistingSource(uri.toString(), UriKind.PACKAGE_URI);
   }
 
   /**
    * Returns `true` if [uri] is a `package` URI.
    */
   static bool isPackageUri(Uri uri) {
     return uri.scheme == PACKAGE_SCHEME;
   }
 }