Issue 23573. Catch exception during indexing.

pkg/analysis_server/lib/src/services/index/index_contributor.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 services.src.index.index_contributor;
 
 import 'dart:collection' show Queue;
 
 import 'package:analysis_server/analysis/index/index_core.dart';
 import 'package:analysis_server/analysis/index/index_dart.dart';
@@ skipping 22 matching lines @@
   CompilationUnitElement unitElement = unit.element;
   if (unitElement == null) {
     return;
   }
   // about to index
   bool mayIndex = store.aboutToIndexDart(context, unitElement);
   if (!mayIndex) {
     return;
   }
   // do index
-  unit.accept(new _IndexContributor(store));
-  store.doneIndex();
+  try {
+    unit.accept(new _IndexContributor(store));
+    store.doneIndex();
+  } catch (e) {
+    store.cancelIndexDart();
+    rethrow;
+  }
 }
 
 /**
  * Adds data to [store] based on the resolved HTML [unit].
  */
 void indexHtmlUnit(
     InternalIndexStore store, AnalysisContext context, ht.HtmlUnit unit) {
   // check unit
   if (unit == null) {
     return;
@@ skipping 739 matching lines @@
   }
 
   /**
    * @return `true` if given "node" is part of [PrefixedIdentifier] "prefix.node".
    */
   static bool _isIdentifierInPrefixedIdentifier(SimpleIdentifier node) {
     AstNode parent = node.parent;
     return parent is PrefixedIdentifier && parent.identifier == node;
   }
 }