fix oplog replay segfault SERVER-4350

2 files changed, 2 insertions, 1 deletions

diff --git a/db/dbhelpers.cpp b/db/dbhelpers.cpp
index cc4fdba0bde..33ac9b71298 100644
--- a/db/dbhelpers.cpp
+++ b/db/dbhelpers.cpp
@@ -157,6 +157,7 @@ namespace mongo {
     }
 
     DiskLoc Helpers::findById(NamespaceDetails *d, BSONObj idquery) {
+        assert(d);
         int idxNo = d->findIdIndex();
         uassert(13430, "no _id index", idxNo>=0);
         IndexDetails& i = d->idx( idxNo );
diff --git a/db/oplog.cpp b/db/oplog.cpp
index b77993eca2b..5c1671c1ac8 100644
--- a/db/oplog.cpp
+++ b/db/oplog.cpp
@@ -741,7 +741,7 @@ namespace mongo {
                     // of the form
                     //   { _id:..., { x : {$size:...} }
                     // thus this is not ideal.
-                    else if( Helpers::findById(nsdetails(ns), updateCriteria).isNull() ) {
+                    else if( nsdetails(ns) == NULL || Helpers::findById(nsdetails(ns), updateCriteria).isNull() ) {
                         failedUpdate = true; 
                     }
                     else {