From 4d65f622f31e740df113da7c2b79aee4a82814ff Mon Sep 17 00:00:00 2001
From: Konstantin Knizhnik <knizhnik@garret.ru>
Date: Fri, 11 Feb 2022 15:09:08 +0300
Subject: [PATCH] Handle zero number of versions in PersistentBatchAVLProver

---
 .../authds/avltree/batch/PersistentBatchAVLProver.scala    | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/main/scala/scorex/crypto/authds/avltree/batch/PersistentBatchAVLProver.scala b/src/main/scala/scorex/crypto/authds/avltree/batch/PersistentBatchAVLProver.scala
index b9d8d29b..18bd9e8b 100644
--- a/src/main/scala/scorex/crypto/authds/avltree/batch/PersistentBatchAVLProver.scala
+++ b/src/main/scala/scorex/crypto/authds/avltree/batch/PersistentBatchAVLProver.scala
@@ -55,8 +55,11 @@ object PersistentBatchAVLProver {
         case Some(ver) => rollback(ver).get
         case None => generateProofAndUpdateStorage(additionalData) //to initialize storage and clear prover's state
       }).ensuring { _ =>
-        storage.version.get.sameElements(avlProver.digest) &&
-          (!paranoidChecks || Try(avlProver.checkTree(true)).isSuccess)
+        storage.version match {
+          case Some(ver) => ver.sameElements(avlProver.digest) &&
+            (!paranoidChecks || Try(avlProver.checkTree(true)).isSuccess)
+          case None => true
+        }
       }
     }
   }