SERVER-18170 Forbid creation of _id index if it's also a sparse index

1 files changed, 4 insertions, 0 deletions

diff --git a/src/mongo/db/catalog/index_catalog.cpp b/src/mongo/db/catalog/index_catalog.cpp
index c1ce3e8fae4..9aefade3380 100644
--- a/src/mongo/db/catalog/index_catalog.cpp
+++ b/src/mongo/db/catalog/index_catalog.cpp
@@ -596,6 +596,10 @@ namespace {
             if ( filterElement ) {
                 return Status( ErrorCodes::CannotCreateIndex, "_id index cannot be partial" );
             }
+
+            if ( isSparse ) {
+                return Status( ErrorCodes::CannotCreateIndex, "_id index cannot be sparse" );
+            }
         }
         else {
             // for non _id indexes, we check to see if replication has turned off all indexes