server: Fix corrupting balances while adding repeated blocks

server/app/com/xsn/explorer/processors/BlockEventsProcessor.scala

@@ -86,8 +86,20 @@ class BlockEventsProcessor @Inject() (
     }
 
     def onMissingBlock(): FutureApplicationResult[Unit] = {
-      val command = DatabaseSeeder.CreateBlockCommand(newBlock, newTransactions)
-      databaseSeeder.insertPendingBlock(command)
+      blockDataHandler
+          .getBy(newBlock.hash)
+          .flatMap {
+            case Good(_) =>
+              logger.info(s"The block ${newBlock.hash.string} is not missing but duplicated, ignoring")
+              Future.successful { Good(()) }
+
+            case Bad(One(BlockNotFoundError)) =>
+              val command = DatabaseSeeder.CreateBlockCommand(newBlock, newTransactions)
+              databaseSeeder.insertPendingBlock(command)
+
+            case Bad(errors) =>
+              Future.successful(Bad(errors))
+          }
     }
 
     val result = for {

server/test/com/xsn/explorer/processors/BlockEventsProcessorSpec.scala

@@ -1,7 +1,7 @@
 package com.xsn.explorer.processors
 
-import com.xsn.explorer.data.anorm.dao.{BalancePostgresDAO, BlockPostgresDAO, TransactionPostgresDAO}
-import com.xsn.explorer.data.anorm.{BlockPostgresDataHandler, DatabasePostgresSeeder}
+import com.xsn.explorer.data.anorm.dao.{BalancePostgresDAO, BlockPostgresDAO, StatisticsPostgresDAO, TransactionPostgresDAO}
+import com.xsn.explorer.data.anorm.{BlockPostgresDataHandler, DatabasePostgresSeeder, StatisticsPostgresDataHandler}
 import com.xsn.explorer.data.async.{BlockFutureDataHandler, DatabaseFutureSeeder}
 import com.xsn.explorer.data.common.PostgresDataHandlerSpec
 import com.xsn.explorer.helpers.Executors._
@@ -88,6 +88,25 @@ class BlockEventsProcessorSpec extends PostgresDataHandlerSpec with ScalaFutures
         verifyBlockchain(blocks)
       }
     }
+
+    "processing a repeated missing block doesn't affect the balance" in {
+      val block1 = BlockLoader.get("000003fb382f6892ae96594b81aa916a8923c70701de4e7054aac556c7271ef7")
+      val block2 = BlockLoader.get("000004645e2717b556682e3c642a4c6e473bf25c653ff8e8c114a3006040ffb8")
+      val block3 = BlockLoader.get("00000766115b26ecbc09cd3a3db6870fdaf2f049d65a910eb2f2b48b566ca7bd")
+
+      List(block1, block2, block3).map(dataHandler.upsert).foreach(_.isGood mustEqual true)
+
+      whenReady(processor.newLatestBlock(block1.hash)) { result =>
+        result.isGood mustEqual true
+        val blocks = List(block1, block2, block3)
+        verifyBlockchain(blocks)
+
+        val statsDataHandler = new StatisticsPostgresDataHandler(database, new StatisticsPostgresDAO)
+        val stats = statsDataHandler.getStatistics().get
+        stats.totalSupply.isEmpty mustEqual true
+        stats.circulatingSupply.isEmpty mustEqual true
+      }
+    }
   }
 
   private def verifyBlockchain(blocks: List[Block]) = {