ETCM-987: Latest block not found bug (#1076)

Author: AnastasiiaL

src/main/scala/io/iohk/ethereum/blockchain/sync/fast/FastSync.scala

@@ -567,13 +567,14 @@ class FastSync(
 
     // TODO [ETCM-676]: Move to blockchain and make sure it's atomic
     private def discardLastBlocks(startBlock: BigInt, blocksToDiscard: Int): Unit = {
+      // TODO (maybe ETCM-77): Manage last checkpoint number too
+      appStateStorage.putBestBlockNumber((startBlock - blocksToDiscard - 1).max(0)).commit()
+
       (startBlock to ((startBlock - blocksToDiscard).max(1)) by -1).foreach { n =>
         blockchainReader.getBlockHeaderByNumber(n).foreach { headerToRemove =>
           blockchain.removeBlock(headerToRemove.hash, withState = false)
         }
       }
-      // TODO (maybe ETCM-77): Manage last checkpoint number too
-      appStateStorage.putBestBlockNumber((startBlock - blocksToDiscard - 1).max(0)).commit()
     }
 
     private def validateHeader(header: BlockHeader, peer: Peer): Either[HeaderProcessingResult, BlockHeader] = {

src/main/scala/io/iohk/ethereum/domain/BlockchainReader.scala

@@ -180,7 +180,7 @@ class BlockchainReader(
 
   /** Returns a block hash given a block number
     *
-    * @param number Number of the searchead block
+    * @param number Number of the searched block
     * @return Block hash if found
     */
   private def getHashByBlockNumber(number: BigInt): Option[ByteString] =