Error handling and code cleanup

pkg/analysis_server/lib/src/protocol.dart

Index: pkg/analysis_server/lib/src/protocol.dart
diff --git a/pkg/analysis_server/lib/src/protocol.dart b/pkg/analysis_server/lib/src/protocol.dart
index 5827d47cd5b1c434e64a3e58ed9525046796b92e..123214f7214eaa648e42d342629559532ccd6640 100644
--- a/pkg/analysis_server/lib/src/protocol.dart
+++ b/pkg/analysis_server/lib/src/protocol.dart
@@ -77,9 +77,11 @@ class Request {
       String method = result[Request.METHOD];
       Map<String, Object> params = result[Request.PARAMS];
       Request request = new Request(id, method);
-      params.forEach((String key, Object value) {
-        request.setParameter(key, value);
-      });
+      if (params != null) {
+        params.forEach((String key, Object value) {
+          request.setParameter(key, value);
+        });
+      }
       return request;
     } catch (exception) {
       return null;