refs #5282 i lied, the ydb layer needed some fixes for txnless descriptor updates :)

git-svn-id: file:///svn/toku/tokudb@45959 c7de825b-a66e-492c-adef-691d508d4ae1

src/ydb_db.cc

@@ -483,11 +483,11 @@ toku_db_change_descriptor(DB *db, DB_TXN* txn, const DBT* descriptor, u_int32_t
     BOOL update_cmp_descriptor = ((flags & DB_UPDATE_CMP_DESCRIPTOR) != 0);
 
     toku_init_dbt(&old_descriptor);
-    if (!db_opened(db) || !txn || !descriptor || (descriptor->size>0 && !descriptor->data)){
+    if (!db_opened(db) || !descriptor || (descriptor->size>0 && !descriptor->data)){
         r = EINVAL;
         goto cleanup;
     }
-    if (txn->parent != NULL) {
+    if (txn && txn->parent != NULL) {
         r = EINVAL; // cannot have a parent if you are a resetting op
         goto cleanup;
     }