Fix handling of reorgs

- apply snapshot in case of a reorg and if the snapshot is still empty.
Set chain height to genesis height.
- Handle case if cycles are empty
- Add checks for getLast for linked lists

core/src/main/java/bisq/core/dao/governance/myvote/MyVoteListService.java

@@ -122,6 +122,7 @@ public class MyVoteListService implements PersistedDataHost {
 
     public List<MyVote> getMyVoteListForCycle() {
         return myVoteList.getList().stream()
+                .filter(e -> daoStateService.getCurrentCycle() != null)
                 .filter(e -> daoStateService.getCurrentCycle().isInCycle(e.getHeight()))
                 .collect(Collectors.toList());
     }

core/src/main/java/bisq/core/dao/governance/period/CycleService.java

@@ -105,9 +105,9 @@ public class CycleService implements DaoStateListener, DaoSetupService {
         // applied the new cycle yet. But the first block of the old cycle will always be the same as the
         // first block of the new cycle.
         Cycle cycle = null;
-        if (blockHeight != genesisBlockHeight && isFirstBlockAfterPreviousCycle(blockHeight, cycles)) {
+        if (blockHeight != genesisBlockHeight && isFirstBlockAfterPreviousCycle(blockHeight, cycles) && !cycles.isEmpty()) {
             // We have the not update daoStateService.getCurrentCycle() so we grab here the previousCycle
-            final Cycle previousCycle = cycles.getLast();
+            Cycle previousCycle = cycles.getLast();
             // We create the new cycle as clone of the previous cycle and only if there have been change events we use
             // the new values from the change event.
             cycle = createNewCycle(blockHeight, previousCycle);

core/src/main/java/bisq/core/dao/governance/period/PeriodService.java

@@ -29,6 +29,8 @@ import java.util.Optional;
 
 import lombok.extern.slf4j.Slf4j;
 
+import javax.annotation.Nullable;
+
 @Slf4j
 public final class PeriodService {
     private final DaoStateService daoStateService;
@@ -52,6 +54,7 @@ public final class PeriodService {
         return daoStateService.getCycles();
     }
 
+    @Nullable
     public Cycle getCurrentCycle() {
         return daoStateService.getCurrentCycle();
     }
@@ -65,7 +68,9 @@ public final class PeriodService {
     }
 
     public DaoPhase.Phase getCurrentPhase() {
-        return getCurrentCycle().getPhaseForHeight(this.getChainHeight()).get();
+        return getCurrentCycle() != null ?
+                getCurrentCycle().getPhaseForHeight(this.getChainHeight()).orElse(DaoPhase.Phase.UNDEFINED) :
+                DaoPhase.Phase.UNDEFINED;
     }
 
     public boolean isFirstBlockInCycle(int height) {

core/src/main/java/bisq/core/dao/node/BsqNode.java

@@ -137,7 +137,7 @@ public abstract class BsqNode implements DaoSetupService {
 
     @SuppressWarnings("WeakerAccess")
     protected void onInitialized() {
-        applySnapshot();
+        daoStateSnapshotService.applySnapshot(false);
 
         if (p2PService.isBootstrapped()) {
             log.info("onAllServicesInitialized: isBootstrapped");
@@ -187,20 +187,11 @@ public abstract class BsqNode implements DaoSetupService {
 
     @SuppressWarnings("WeakerAccess")
     protected void startReOrgFromLastSnapshot() {
-        applySnapshot();
+        daoStateSnapshotService.applySnapshot(true);
         startParseBlocks();
     }
 
     protected boolean isBlockAlreadyAdded(RawBlock rawBlock) {
         return daoStateService.getBlockAtHeight(rawBlock.getHeight()).isPresent();
     }
-
-
-    ///////////////////////////////////////////////////////////////////////////////////////////
-    // Private
-    ///////////////////////////////////////////////////////////////////////////////////////////
-
-    private void applySnapshot() {
-        daoStateSnapshotService.applySnapshot();
-    }
 }

core/src/main/java/bisq/core/dao/node/parser/BlockParser.java

@@ -121,7 +121,7 @@ public class BlockParser {
 
     private void validateIfBlockIsConnecting(RawBlock rawBlock) throws BlockNotConnectingException {
         LinkedList<Block> blocks = daoStateService.getBlocks();
-        if (!isBlockConnecting(rawBlock, blocks)) {
+        if (!isBlockConnecting(rawBlock, blocks) && !blocks.isEmpty()) {
             Block last = blocks.getLast();
             log.warn("addBlock called with a not connecting block. New block:\n" +
                             "height()={}, hash()={}, lastBlock.height()={}, lastBlock.hash()={}",

core/src/main/java/bisq/core/dao/state/DaoStateService.java

@@ -55,6 +55,8 @@ import java.util.stream.Stream;
 
 import lombok.extern.slf4j.Slf4j;
 
+import javax.annotation.Nullable;
+
 import static com.google.common.base.Preconditions.checkArgument;
 
 /**
@@ -99,6 +101,8 @@ public class DaoStateService implements DaoSetupService {
     ///////////////////////////////////////////////////////////////////////////////////////////
 
     public void applySnapshot(DaoState snapshot) {
+        log.info("Apply snapshot with chain height {}", snapshot.getChainHeight());
+
         daoState.setChainHeight(snapshot.getChainHeight());
 
         daoState.getBlocks().clear();
@@ -155,8 +159,9 @@ public class DaoStateService implements DaoSetupService {
         return daoState.getCycles();
     }
 
+    @Nullable
     public Cycle getCurrentCycle() {
-        return getCycles().getLast();
+        return !getCycles().isEmpty() ? getCycles().getLast() : null;
     }
 
     public Optional<Cycle> getCycle(int height) {

core/src/main/java/bisq/core/dao/state/DaoStateSnapshotService.java

@@ -77,6 +77,7 @@ public class DaoStateSnapshotService implements DaoStateListener {
         // different to our current height.
         boolean noSnapshotCandidateOrDifferentHeight = snapshotCandidate == null || snapshotCandidate.getChainHeight() != chainHeight;
         if (isSnapshotHeight(chainHeight) &&
+                !daoStateService.getBlocks().isEmpty() &&
                 isValidHeight(daoStateService.getBlocks().getLast().getHeight()) &&
                 noSnapshotCandidateOrDifferentHeight) {
             // At trigger event we store the latest snapshotCandidate to disc
@@ -108,7 +109,7 @@ public class DaoStateSnapshotService implements DaoStateListener {
     // API
     ///////////////////////////////////////////////////////////////////////////////////////////
 
-    public void applySnapshot() {
+    public void applySnapshot(boolean fromReorg) {
         DaoState persisted = daoStateStorageService.getPersistedBsqState();
         if (persisted != null) {
             LinkedList<Block> blocks = persisted.getBlocks();
@@ -117,6 +118,11 @@ public class DaoStateSnapshotService implements DaoStateListener {
                 log.info("applySnapshot from persisted daoState with height of last block {}", heightOfLastBlock);
                 if (isValidHeight(heightOfLastBlock))
                     daoStateService.applySnapshot(persisted);
+            } else if (fromReorg) {
+                log.info("We got a reorg and we want to apply the snapshot but it is empty. That is expected in the first blocks until the " +
+                        "first snapshot has been created. We use our applySnapshot method and restart from the genesis tx");
+                persisted.setChainHeight(genesisTxInfo.getGenesisBlockHeight());
+                daoStateService.applySnapshot(persisted);
             }
         } else {
             log.info("Try to apply snapshot but no stored snapshot available. That is expected at first blocks.");