do not create extra NamespaceString

Author: erh

src/mongo/db/instance.cpp

@@ -209,7 +209,7 @@ namespace mongo {
                 audit::logQueryAuthzCheck(client, ns, q.query, status.code());
                 uassertStatusOK(status);
             }
-            dbresponse.exhaustNS = runQuery(txn, m, q, op, *resp, fromDBDirectClient);
+            dbresponse.exhaustNS = runQuery(txn, m, q, ns, op, *resp, fromDBDirectClient);
             verify( !resp->empty() );
         }
         catch ( SendStaleConfigException& e ){

src/mongo/db/query/find.cpp

@@ -540,11 +540,11 @@ namespace mongo {
     std::string runQuery(OperationContext* txn,
                          Message& m,
                          QueryMessage& q,
+                         const NamespaceString& nss,
                          CurOp& curop,
                          Message &result,
                          bool fromDBDirectClient) {
         // Validate the namespace.
-        const NamespaceString nss(q.ns);
         uassert(16256, str::stream() << "Invalid ns [" << nss.ns() << "]", nss.isValid());
 
         // Set curop information.

src/mongo/db/query/find.h

@@ -74,6 +74,7 @@ namespace mongo {
     std::string runQuery(OperationContext* txn,
                          Message& m,
                          QueryMessage& q,
+                         const NamespaceString& ns,
                          CurOp& curop,
                          Message &result,
                          bool fromDBDirectClient);