Merge pull request #2183 from yang-g/nil

Only copy call details when the status is ok.

src/cpp/server/server.cc

@@ -368,8 +368,11 @@ Server::GenericAsyncRequest::GenericAsyncRequest(
 
 bool Server::GenericAsyncRequest::FinalizeResult(void** tag, bool* status) {
   // TODO(yangg) remove the copy here.
-  static_cast<GenericServerContext*>(context_)->method_ = call_details_.method;
-  static_cast<GenericServerContext*>(context_)->host_ = call_details_.host;
+  if (*status) {
+    static_cast<GenericServerContext*>(context_)->method_ =
+        call_details_.method;
+    static_cast<GenericServerContext*>(context_)->host_ = call_details_.host;
+  }
   gpr_free(call_details_.method);
   gpr_free(call_details_.host);
   return BaseAsyncRequest::FinalizeResult(tag, status);