mojo: fail gracefully if ServiceRegistry can't find ServiceConnector

mojo/public/cpp/application/lib/service_registry.cc

Index: mojo/public/cpp/application/lib/service_registry.cc
diff --git a/mojo/public/cpp/application/lib/service_registry.cc b/mojo/public/cpp/application/lib/service_registry.cc
index ea22ec4e5be62684ed0366a468325bc83cc4791e..86a52f3ea16650ff933abb4b3e9134d5ba5468df 100644
--- a/mojo/public/cpp/application/lib/service_registry.cc
+++ b/mojo/public/cpp/application/lib/service_registry.cc
@@ -58,7 +58,9 @@ void ServiceRegistry::ConnectToService(const mojo::String& service_url,
                                        const mojo::String& service_name,
                                        ScopedMessagePipeHandle client_handle,
                                        const mojo::String& requestor_url) {
-  if (!application_->AllowIncomingConnection(service_name, requestor_url)) {
+  if (!application_->AllowIncomingConnection(service_name, requestor_url) ||
+      name_to_service_connector_.find(service_name) ==

[viettrungluu, 2014/06/18 14:52:06]

I wonder if we shouldn't reverse the order of the checks, i.e., not call
application_->AllowIncomingConnection() on nonexistent service names.

(Just a thought. I'll defer to Dave's opinion on this.)

[tim (not reviewing), 2014/06/18 20:18:20]

I like that better than what I had. It seems more in line with the expectation
of AllowIncomingConnection that it only makes decisions for realistic
connections. Also, the way the test was structured was to increment a
num_connected_ bool as a side effect of an overridden AllowIncomingConnection,
which was weird in this case where the ++ happened but the connection didn't.
Now I can add an additional assertion to the unit test.  Done.

+          name_to_service_connector_.end()) {
     client_handle.reset();
     return;
   }