fix(model-client): drop local changes when the synchronization fails

When there is an exception during the merge of a version
received from the server with the local version,
just replace the local version with the remote version.
Losing some recent changes is less critical that getting
out of sync with the server.

Author: slisson

model-client/src/commonMain/kotlin/org/modelix/model/client2/ReplicatedModel.kt

@@ -91,8 +91,13 @@ class ReplicatedModel(val client: IModelClientV2, val branchRef: BranchReference
             if (newRemoteVersion.getContentHash() != localVersion.getContentHash()) {
                 otBranch.runWrite {
                     applyPendingLocalChanges()
-                    localVersion = VersionMerger(newRemoteVersion.store, client.getIdGenerator())
-                        .mergeChange(localVersion, newRemoteVersion)
+                    try {
+                        localVersion = VersionMerger(newRemoteVersion.store, client.getIdGenerator())
+                            .mergeChange(localVersion, newRemoteVersion)
+                    } catch (ex: Exception) {
+                        LOG.warn(ex) { "Failed to merge remote version $newRemoteVersion into local version $localVersion. Resetting to remote version." }
+                        localVersion = newRemoteVersion
+                    }
                     rawBranch.writeTransaction.tree = localVersion.tree
                 }
             }
@@ -136,6 +141,10 @@ class ReplicatedModel(val client: IModelClientV2, val branchRef: BranchReference
         Started,
         Disposed
     }
+
+    companion object {
+        private val LOG = mu.KotlinLogging.logger {  }
+    }
 }
 
 fun IModelClientV2.getReplicatedModel(branchRef: BranchReference, query: ModelQuery? = null): ReplicatedModel {