Remove duplicated stack trace from error notifications

pkg/analysis_server/lib/src/analysis_server.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 analysis.server;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:core' hide Resource;
 import 'dart:math' show max;
@@ skipping 874 matching lines @@
   /**
    * Send the given [response] to the client.
    */
   void sendResponse(Response response) {
     channel.sendResponse(response);
   }
 
   /**
    * Sends a `server.error` notification.
    */
-  void sendServerErrorNotification(String msg, exception, stackTrace,
+  void sendServerErrorNotification(String message, exception, stackTrace,
       {bool fatal: false}) {
-    // prepare exception.toString()
-    String exceptionString;
+    StringBuffer buffer = new StringBuffer();
     if (exception != null) {
-      exceptionString = exception.toString();
+      buffer.write(exception);
     } else {
-      exceptionString = 'null exception';
+      buffer.write('null exception');
     }
-    // prepare message
-    String message = msg != null ? '$msg\n$exceptionString' : exceptionString;
-    // prepare stackTrace.toString()
-    String stackTraceString;
     if (stackTrace != null) {
-      stackTraceString = stackTrace.toString();
-    } else {
+      buffer.writeln();
+      buffer.write(stackTrace);
+    } else if (exception is! CaughtException) {
       try {
         throw 'ignored';
       } catch (ignored, stackTrace) {
-        stackTraceString = stackTrace.toString();
-      }
-      if (stackTraceString == null) {
-        // This code should be unreachable.
-        stackTraceString = 'null stackTrace';
+        buffer.writeln();
+        buffer.write(stackTrace);
       }
     }
     // send the notification
     channel.sendNotification(
-        new ServerErrorParams(fatal, message, stackTraceString)
+        new ServerErrorParams(fatal, message, buffer.toString())
             .toNotification());
   }
 
   /**
    * Send status notification to the client. The `operation` is the operation
    * being performed or `null` if analysis is complete.
    */
   void sendStatusNotification(ServerOperation operation) {
     // Only send status when subscribed.
     if (!serverServices.contains(ServerService.STATUS)) {
@@ skipping 740 matching lines @@
   /**
    * The [PerformanceTag] for time spent in server request handlers.
    */
   static PerformanceTag serverRequests = new PerformanceTag('serverRequests');
 
   /**
    * The [PerformanceTag] for time spent in split store microtasks.
    */
   static PerformanceTag splitStore = new PerformanceTag('splitStore');
 }