gracefully handle internal exceptions during request

pkg/analysis_server/lib/src/analysis_server.dart

Index: pkg/analysis_server/lib/src/analysis_server.dart
diff --git a/pkg/analysis_server/lib/src/analysis_server.dart b/pkg/analysis_server/lib/src/analysis_server.dart
index d5944ba01154dbca78735eed012ebebd317f3400..c4ca2d2330a7d256fb6cd7d4dea42da5dee2875b 100644
--- a/pkg/analysis_server/lib/src/analysis_server.dart
+++ b/pkg/analysis_server/lib/src/analysis_server.dart
@@ -389,23 +389,32 @@ class AnalysisServer {
    * Handle a [request] that was read from the communication channel.
    */
   void handleRequest(Request request) {
-    int count = handlers.length;
-    for (int i = 0; i < count; i++) {
-      try {
-        Response response = handlers[i].handleRequest(request);
-        if (response == Response.DELAYED_RESPONSE) {
+    runZoned(() {
+      int count = handlers.length;
+      for (int i = 0; i < count; i++) {
+        try {
+          Response response = handlers[i].handleRequest(request);
+          if (response == Response.DELAYED_RESPONSE) {
+            return;
+          }
+          if (response != null) {
+            channel.sendResponse(response);
+            return;
+          }
+        } on RequestFailure catch (exception) {
+          channel.sendResponse(exception.response);
           return;
-        }
-        if (response != null) {
+        } catch (exception, stackTrace) {
+          _sendServerErrorNotification(exception, stackTrace);

[Brian Wilkerson, 2014/09/11 22:48:07]

Does this mean that we are sending a notification AND a response with the same
error information? If so, that seems wrong.

[danrubel, 2014/09/11 23:32:08]

They are different. Notification is structured to include a stack trace and is
standard mechanism for returning internal errors. Response just indicates that
the request failed for some unknown reason. We can remove the response entirely,
but it seemed correct to complete the outstanding request so that the client is
not left hanging.

+          RequestError error =
+              new RequestError(RequestErrorCode.SERVER_ERROR, 'Server Error');
+          Response response = new Response(request.id, error: error);
           channel.sendResponse(response);
           return;
         }
-      } on RequestFailure catch (exception) {
-        channel.sendResponse(exception.response);
-        return;
       }
-    }
-    channel.sendResponse(new Response.unknownRequest(request));
+      channel.sendResponse(new Response.unknownRequest(request));
+    }, onError: _sendServerErrorNotification);
   }
 
   /**