Ensure that AnalysisContext futures are completed when context disposed.

pkg/analyzer/lib/src/generated/engine.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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine;
 
 import "dart:math" as math;
@@ skipping 1763 matching lines @@
     }
     return new AnalysisCache(
         <CachePartition>[
             AnalysisEngine.instance.partitionManager.forSdk(sdk),
             _privatePartition]);
   }
 
   @override
   void dispose() {
     _disposed = true;
+    for (List<PendingFuture> pendingFutures in _pendingFutureSources.values) {
+      for (PendingFuture pendingFuture in pendingFutures) {
+        pendingFuture.forciblyComplete();
+      }
+    }
+    _pendingFutureSources.clear();
   }
 
   @override
   bool exists(Source source) {
     if (source == null) {
       return false;
     }
     if (_contentCache.getContents(source) != null) {
       return true;
     }
@@ skipping 12553 matching lines @@
    * If the [computeValue] still returns null after there is no further
    * analysis to be done for [source], then the future will be completed with
    * the error AnalysisNotScheduledError.
    *
    * Since [computeValue] will be called while the state of analysis is being
    * updated, it should be free of side effects so that it doesn't cause
    * reentrant changes to the analysis state.
    */
   CancelableFuture<T> computeAsync(Source source, T
       computeValue(SourceEntry sourceEntry)) {
+    if (_context.isDisposed) {
+      // No further analysis is expected, so return a future that completes
+      // immediately with AnalysisNotScheduledError.
+      return new CancelableFuture.error(new AnalysisNotScheduledError());
+    }
     SourceEntry sourceEntry = _context.getReadableSourceEntryOrNull(source);
     if (sourceEntry == null) {
       return new CancelableFuture.error(new AnalysisNotScheduledError());
     }
     PendingFuture pendingFuture =
         new PendingFuture<T>(_context, source, computeValue);
     if (!pendingFuture.evaluate(sourceEntry)) {
       _context._pendingFutureSources.putIfAbsent(
           source,
           () => <PendingFuture>[]).add(pendingFuture);
@@ skipping 47 matching lines @@
 
   @override
   Object visitPolymerTagDartElement(PolymerTagDartElement element) {
     if (element.name == PolymerHtmlUnitBuilder_this._elementName) {
       throw new PolymerHtmlUnitBuilder_FoundTagDartElementError(
           element as PolymerTagDartElementImpl);
     }
     return null;
   }
 }