Fixes for adding/removing pubspecs to/from roots.

pkg/analysis_server/lib/src/context_manager.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 context.directory.manager;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analysis_server/src/package_map_provider.dart';
@@ skipping 245 matching lines @@
     }
     // handle the change
     switch (event.type) {
       case ChangeType.ADD:
         if (_isInPackagesDir(path, folder)) {
           // TODO(paulberry): perhaps we should only skip packages dirs if
           // there is a pubspec.yaml?
           break;
         }
         Resource resource = resourceProvider.getResource(path);
-        // pubspec was added, extract a new context
-        if (_isPubspec(path)) {
+        // pubspec was added in a sub-folder, extract a new context
+        if (_isPubspec(path) && info.isRoot && !info.isPubspec(path)) {
           _extractContext(info, resource);
           return;
         }
         // If the file went away and was replaced by a folder before we
         // had a chance to process the event, resource might be a Folder.  In
         // that case don't add it.
         if (resource is File) {
           File file = resource;
           if (_shouldFileBeAnalyzed(file)) {
             ChangeSet changeSet = new ChangeSet();
             Source source = file.createSource();
             changeSet.addedSource(source);
             applyChangesToContext(folder, changeSet);
             info.sources[path] = source;
           }
         }
         break;
       case ChangeType.REMOVE:
         // pubspec was removed, merge the context into its parent
-        if (info.isPubspec(path)) {
+        if (info.isPubspec(path) && !info.isRoot) {
           _mergeContext(info);
           return;
         }
         Source source = info.sources[path];
         if (source != null) {
           ChangeSet changeSet = new ChangeSet();
           changeSet.removedSource(source);
           applyChangesToContext(folder, changeSet);
           info.sources.remove(path);
         }
@@ skipping 145 matching lines @@
   Set<String> packageMapDependencies;
 
   _ContextInfo(this.folder, this.children) {
     pubspecPath = folder.getChild(PUBSPEC_NAME).path;
     for (_ContextInfo child in children) {
       child.parent = this;
     }
   }
 
   /**
+   * Returns `true` if this context is root folder based.
+   */
+  bool get isRoot => parent == null;
+
+  /**
    * Returns `true` if [path] is excluded, as it is in one of the children.
    */
   bool excludes(String path) {
     return children.any((child) {
       return child.folder.contains(path);
     });
   }
 
   /**
    * Returns `true` if [resource] is excldued, as it is in one of the children.
    */
   bool excludesResource(Resource resource) {
     return excludes(resource.path);
   }
 
   /**
    * Returns `true` if [path] is the pubspec file of this context.
    */
   bool isPubspec(String path) {
     return path == pubspecPath;
   }
 }