SERVER-40959 forEachCollectionFromDb() should skip collections that return a NamespaceString of size 0 from UUIDCatalog::lookupNSSByUUID() as it may have been dropped since we aren't holding any locks

1 files changed, 6 insertions, 0 deletions

diff --git a/src/mongo/db/catalog/uuid_catalog_helper.cpp b/src/mongo/db/catalog/uuid_catalog_helper.cpp
index 1ba42ec7b04..49f79e15007 100644
--- a/src/mongo/db/catalog/uuid_catalog_helper.cpp
+++ b/src/mongo/db/catalog/uuid_catalog_helper.cpp
@@ -47,6 +47,12 @@ void forEachCollectionFromDb(
         auto uuid = collectionIt.uuid().get();
         auto nss = uuidCatalog.lookupNSSByUUID(uuid);
 
+        // If the NamespaceString we resolve by the 'uuid' is empty, the collection was dropped
+        // and we should move onto the next one.
+        if (nss.isEmpty()) {
+            continue;
+        }
+
         Lock::CollectionLock clk(opCtx, nss, collLockMode);
 
         auto collection = uuidCatalog.lookupCollectionByUUID(uuid);