Fix for search references when the element is null.

pkg/analysis_server/lib/src/search/search_domain.dart

Index: pkg/analysis_server/lib/src/search/search_domain.dart
diff --git a/pkg/analysis_server/lib/src/search/search_domain.dart b/pkg/analysis_server/lib/src/search/search_domain.dart
index 765598708a8532129a7ec3614e578b85d884960a..903132576b9eefdbaf4cfcfc24d808f395a863d8 100644
--- a/pkg/analysis_server/lib/src/search/search_domain.dart
+++ b/pkg/analysis_server/lib/src/search/search_domain.dart
@@ -75,10 +75,12 @@ class SearchDomainHandler implements protocol.RequestHandler {
     }
     _sendSearchResult(request, result);
     // search elements
-    var computer = new ElementReferencesComputer(searchEngine);
-    List<protocol.SearchResult> results =
-        await computer.compute(element, params.includePotential);
-    _sendSearchNotification(searchId, true, results);
+    if (element != null) {
+      var computer = new ElementReferencesComputer(searchEngine);
+      List<protocol.SearchResult> results =
+          await computer.compute(element, params.includePotential);
+      _sendSearchNotification(searchId, true, results);

[Brian Wilkerson, 2016/11/28 16:40:15]

If element is null, will we still send a search notification? It seems like
clients ought to be able to count on getting at least one notification
indicating that there won't be any more notifications (isLast == true).

[scheglov, 2016/11/28 16:49:40]

We don't need to.

According to the protocol: "If no element was found at the given location, this
field (id) will be absent, and no results will be reported via the
search.results notification."

+    }
   }
 
   Future findMemberDeclarations(protocol.Request request) async {