From e6620180894c3f87a8af6ae2bae9c1e1ae345218 Mon Sep 17 00:00:00 2001
From: supaiku <supaiku@protonmail.com>
Date: Wed, 16 Jan 2019 00:51:17 +0100
Subject: [PATCH 1/5] fix: backport slot check from master

---
 .../__tests__/blockchain.test.ts              | 42 ++++++++++
 .../utils/is-blocked-chained.test.ts          | 80 +++++++++++++++++--
 packages/core-blockchain/src/blockchain.ts    |  7 ++
 .../src/utils/is-block-chained.ts             |  9 ++-
 packages/crypto/src/crypto/slots.ts           |  3 +-
 5 files changed, 129 insertions(+), 12 deletions(-)

diff --git a/packages/core-blockchain/__tests__/blockchain.test.ts b/packages/core-blockchain/__tests__/blockchain.test.ts
index c803f856c7..33036445f0 100644
--- a/packages/core-blockchain/__tests__/blockchain.test.ts
+++ b/packages/core-blockchain/__tests__/blockchain.test.ts
@@ -258,6 +258,48 @@ describe("Blockchain", () => {
         });
     });
 
+    describe("handleIncommingBlock", () => {
+        it("should be ok", () => {
+            const dispatch = blockchain.dispatch;
+            const enqueueBlocks = blockchain.enqueueBlocks;
+            blockchain.dispatch = jest.fn(() => true);
+            blockchain.enqueueBlocks = jest.fn(() => true);
+
+            const block = {
+                height: 100,
+                timestamp: slots.getEpochTime(),
+            };
+
+            blockchain.handleIncomingBlock(block);
+
+            expect(blockchain.dispatch).toHaveBeenCalled();
+            expect(blockchain.enqueueBlocks).toHaveBeenCalled();
+
+            blockchain.dispatch = dispatch;
+            blockchain.enqueueBlocks = enqueueBlocks;
+        });
+
+        it("should not handle block from future slot", () => {
+            const dispatch = blockchain.dispatch;
+            const enqueueBlocks = blockchain.enqueueBlocks;
+            blockchain.dispatch = jest.fn(() => true);
+            blockchain.enqueueBlocks = jest.fn(() => true);
+
+            const block = {
+                height: 100,
+                timestamp: slots.getSlotTime(slots.getNextSlot()),
+            };
+
+            blockchain.handleIncomingBlock(block);
+
+            expect(blockchain.dispatch).not.toHaveBeenCalled();
+            expect(blockchain.enqueueBlocks).not.toHaveBeenCalled();
+
+            blockchain.dispatch = dispatch;
+            blockchain.enqueueBlocks = enqueueBlocks;
+        });
+    });
+
     describe("isSynced", () => {
         describe("with a block param", () => {
             it("should be ok", () => {
diff --git a/packages/core-blockchain/__tests__/utils/is-blocked-chained.test.ts b/packages/core-blockchain/__tests__/utils/is-blocked-chained.test.ts
index 5dfdff6eaf..295e567452 100644
--- a/packages/core-blockchain/__tests__/utils/is-blocked-chained.test.ts
+++ b/packages/core-blockchain/__tests__/utils/is-blocked-chained.test.ts
@@ -1,6 +1,6 @@
 import "jest-extended";
 
-import { models } from "@arkecosystem/crypto";
+import { models, slots } from "@arkecosystem/crypto";
 import { isBlockChained } from "../../src/utils";
 
 describe("isChained", () => {
@@ -8,7 +8,7 @@ describe("isChained", () => {
         const previousBlock = {
             data: {
                 id: "1",
-                timestamp: 1,
+                timestamp: slots.getSlotTime(0),
                 height: 1,
                 previousBlock: null,
             },
@@ -17,20 +17,20 @@ describe("isChained", () => {
         const nextBlock = {
             data: {
                 id: "2",
-                timestamp: 2,
+                timestamp: slots.getSlotTime(1),
                 height: 2,
                 previousBlock: "1",
             },
-        }  as models.IBlock;
+        } as models.IBlock;
 
         expect(isBlockChained(previousBlock, nextBlock)).toBeTrue();
     });
 
-    it("should not be ok", () => {
+    it("should not chain when previous block does not match", () => {
         const previousBlock = {
             data: {
                 id: "2",
-                timestamp: 2,
+                timestamp: slots.getSlotTime(0),
                 height: 2,
                 previousBlock: null,
             },
@@ -39,8 +39,74 @@ describe("isChained", () => {
         const nextBlock = {
             data: {
                 id: "1",
-                timestamp: 1,
+                timestamp: slots.getSlotTime(1),
+                height: 3,
+                previousBlock: "1",
+            },
+        } as models.IBlock;
+
+        expect(isBlockChained(previousBlock, nextBlock)).toBeFalse();
+    });
+
+    it("should not chain when next height is not plus 1", () => {
+        const previousBlock = {
+            data: {
+                id: "1",
+                timestamp: slots.getSlotTime(0),
+                height: 1,
+                previousBlock: null,
+            },
+        } as models.IBlock;
+
+        const nextBlock = {
+            data: {
+                id: "2",
+                timestamp: slots.getSlotTime(1),
+                height: 3,
+                previousBlock: "1",
+            },
+        } as models.IBlock;
+
+        expect(isBlockChained(previousBlock, nextBlock)).toBeFalse();
+    });
+
+    it("should not chain when same slot", () => {
+        const previousBlock = {
+            data: {
+                id: "1",
+                timestamp: slots.getSlotTime(0),
+                height: 1,
+                previousBlock: null,
+            },
+        } as models.IBlock;
+
+        const nextBlock = {
+            data: {
+                id: "2",
+                timestamp: slots.getSlotTime(0),
+                height: 3,
+                previousBlock: "1",
+            },
+        } as models.IBlock;
+
+        expect(isBlockChained(previousBlock, nextBlock)).toBeFalse();
+    });
+
+    it("should not chain when lower slot", () => {
+        const previousBlock = {
+            data: {
+                id: "1",
+                timestamp: slots.getSlotTime(1),
                 height: 1,
+                previousBlock: null,
+            },
+        } as models.IBlock;
+
+        const nextBlock = {
+            data: {
+                id: "2",
+                timestamp: slots.getSlotTime(0),
+                height: 3,
                 previousBlock: "1",
             },
         } as models.IBlock;
diff --git a/packages/core-blockchain/src/blockchain.ts b/packages/core-blockchain/src/blockchain.ts
index a595dfe786..6487ce87e2 100644
--- a/packages/core-blockchain/src/blockchain.ts
+++ b/packages/core-blockchain/src/blockchain.ts
@@ -231,6 +231,13 @@ export class Blockchain implements blockchain.IBlockchain {
             )} from ${block.ip}`,
         );
 
+        const currentSlot = slots.getSlotNumber();
+        const receivedSlot = slots.getSlotNumber(block.timestamp);
+        if (receivedSlot > currentSlot) {
+            logger.info(`Discarded block ${block.height.toLocaleString()} because it takes a future slot.`);
+            return;
+        }
+
         if (this.state.started && this.state.blockchain.value === "idle") {
             this.dispatch("NEWBLOCK");
             this.enqueueBlocks([block]);
diff --git a/packages/core-blockchain/src/utils/is-block-chained.ts b/packages/core-blockchain/src/utils/is-block-chained.ts
index 6b6d7f0bc0..5f3396a3e2 100644
--- a/packages/core-blockchain/src/utils/is-block-chained.ts
+++ b/packages/core-blockchain/src/utils/is-block-chained.ts
@@ -1,9 +1,12 @@
-import { models } from "@arkecosystem/crypto";
+import { models, slots } from "@arkecosystem/crypto";
 
 export const isBlockChained = (previousBlock: models.IBlock, nextBlock: models.IBlock): boolean => {
     const followsPrevious = nextBlock.data.previousBlock === previousBlock.data.id;
-    const isFuture = nextBlock.data.timestamp > previousBlock.data.timestamp;
     const isPlusOne = nextBlock.data.height === previousBlock.data.height + 1;
 
-    return followsPrevious && isFuture && isPlusOne;
+    const previousSlot = slots.getSlotNumber(previousBlock.data.timestamp);
+    const nextSlot = slots.getSlotNumber(nextBlock.data.timestamp);
+    const isAfterPreviousSlot = previousSlot < nextSlot;
+
+    return followsPrevious && isPlusOne && isAfterPreviousSlot;
 };
diff --git a/packages/crypto/src/crypto/slots.ts b/packages/crypto/src/crypto/slots.ts
index 540e72b1c1..86e2112c80 100644
--- a/packages/crypto/src/crypto/slots.ts
+++ b/packages/crypto/src/crypto/slots.ts
@@ -91,7 +91,6 @@ class Slots {
 
     /**
      * Get the next slot number.
-     * @return {Number}
      */
     public getNextSlot(): number {
         return this.getSlotNumber() + 1;
@@ -125,4 +124,4 @@ class Slots {
     }
 }
 
-export const slots = new Slots();
\ No newline at end of file
+export const slots = new Slots();

From 533be5e69d06901066201439b0ff443ce37d2573 Mon Sep 17 00:00:00 2001
From: supaiku <supaiku@protonmail.com>
Date: Wed, 16 Jan 2019 02:42:25 +0100
Subject: [PATCH 2/5] refactor: add ExceptionHandler to BlockProcessor to
 handle exceptional blocks separately

---
 .../src/processor/block-processor.ts          | 29 ++++++------
 .../processor/handlers/exception-handler.ts   | 21 +++++++++
 .../src/processor/handlers/index.ts           |  1 +
 packages/core-blockchain/src/state-machine.ts |  4 +-
 .../src/utils/validate-generator.ts           |  6 +--
 .../src/repositories/blocks.ts                |  2 +-
 packages/core-database/src/wallet-manager.ts  |  4 +-
 packages/crypto/src/crypto/crypto.ts          | 13 ++++--
 packages/crypto/src/models/block.ts           |  6 ++-
 packages/crypto/src/models/transaction.ts     |  9 +++-
 .../src/networks/devnet/exceptions.json       | 44 ++++++++++++++++++-
 11 files changed, 106 insertions(+), 33 deletions(-)
 create mode 100644 packages/core-blockchain/src/processor/handlers/exception-handler.ts

diff --git a/packages/core-blockchain/src/processor/block-processor.ts b/packages/core-blockchain/src/processor/block-processor.ts
index 35d87782ea..47d70f6807 100644
--- a/packages/core-blockchain/src/processor/block-processor.ts
+++ b/packages/core-blockchain/src/processor/block-processor.ts
@@ -2,7 +2,7 @@
 
 import { app } from "@arkecosystem/core-container";
 import { Logger } from "@arkecosystem/core-interfaces";
-import { isException, models } from "@arkecosystem/crypto";
+import { models } from "@arkecosystem/crypto";
 import { Blockchain } from "../blockchain";
 import { isBlockChained } from "../utils/is-block-chained";
 import { validateGenerator } from "../utils/validate-generator";
@@ -11,6 +11,7 @@ import {
     AcceptBlockHandler,
     AlreadyForgedHandler,
     BlockHandler,
+    ExceptionHandler,
     InvalidGeneratorHandler,
     UnchainedHandler,
     VerificationFailedHandler,
@@ -35,6 +36,10 @@ export class BlockProcessor {
     }
 
     public async getHandler(block: models.Block): Promise<BlockHandler> {
+        if (block.isException) {
+            return new ExceptionHandler(this.blockchain, block);
+        }
+
         if (!this.verifyBlock(block)) {
             return new VerificationFailedHandler(this.blockchain, block);
         }
@@ -63,21 +68,13 @@ export class BlockProcessor {
     private verifyBlock(block: models.Block): boolean {
         const verified = block.verification.verified;
         if (!verified) {
-            if (isException(block.data)) {
-                this.logger.warn(
-                    `Block ${block.data.height.toLocaleString()} (${
-                        block.data.id
-                    }) verification failed, but accepting because it is an exception.`,
-                );
-            } else {
-                this.logger.warn(
-                    `Block ${block.data.height.toLocaleString()} (${
-                        block.data.id
-                    }) disregarded because verification failed :scroll:`,
-                );
-                this.logger.warn(JSON.stringify(block.verification, null, 4));
-                return false;
-            }
+            this.logger.warn(
+                `Block ${block.data.height.toLocaleString()} (${
+                    block.data.id
+                }) disregarded because verification failed :scroll:`,
+            );
+            this.logger.warn(JSON.stringify(block.verification, null, 4));
+            return false;
         }
 
         return true;
diff --git a/packages/core-blockchain/src/processor/handlers/exception-handler.ts b/packages/core-blockchain/src/processor/handlers/exception-handler.ts
new file mode 100644
index 0000000000..f40e869f67
--- /dev/null
+++ b/packages/core-blockchain/src/processor/handlers/exception-handler.ts
@@ -0,0 +1,21 @@
+import { BlockProcessorResult } from "../block-processor";
+import { AcceptBlockHandler } from "./accept-block-handler";
+import { BlockHandler } from "./block-handler";
+
+export class ExceptionHandler extends BlockHandler {
+    public async execute(): Promise<BlockProcessorResult> {
+        // Ensure the block has not been forged yet, as an exceptional
+        // block bypasses all other checks.
+        const forgedBlock = await this.blockchain.database.getBlock(this.block.data.id);
+        if (forgedBlock) {
+            super.execute();
+            return BlockProcessorResult.Rejected;
+        }
+
+        this.logger.warn(
+            `Block ${this.block.data.height.toLocaleString()} (${this.block.data.id}) forcibly accepted. :exclamation:`,
+        );
+
+        return new AcceptBlockHandler(this.blockchain, this.block).execute();
+    }
+}
diff --git a/packages/core-blockchain/src/processor/handlers/index.ts b/packages/core-blockchain/src/processor/handlers/index.ts
index 1bdfc241d6..924075ccec 100644
--- a/packages/core-blockchain/src/processor/handlers/index.ts
+++ b/packages/core-blockchain/src/processor/handlers/index.ts
@@ -1,6 +1,7 @@
 export * from "./accept-block-handler";
 export * from "./already-forged-handler";
 export * from "./block-handler";
+export * from "./exception-handler";
 export * from "./invalid-generator-handler";
 export * from "./unchained-handler";
 export * from "./verification-failed-handler";
diff --git a/packages/core-blockchain/src/state-machine.ts b/packages/core-blockchain/src/state-machine.ts
index 6097a8ea97..2d60fc6da6 100644
--- a/packages/core-blockchain/src/state-machine.ts
+++ b/packages/core-blockchain/src/state-machine.ts
@@ -4,7 +4,7 @@ import { app } from "@arkecosystem/core-container";
 import { EventEmitter, Logger } from "@arkecosystem/core-interfaces";
 
 import { roundCalculator } from "@arkecosystem/core-utils";
-import { models, slots } from "@arkecosystem/crypto";
+import { isException, models, slots } from "@arkecosystem/crypto";
 
 import pluralize from "pluralize";
 import { config as localConfig } from "./config";
@@ -320,7 +320,7 @@ blockchainMachine.actionMap = (blockchain: Blockchain) => ({
         }
 
         const empty = !blocks || blocks.length === 0;
-        const chained = !empty && isBlockChained(lastDownloadedBlock, { data: blocks[0] });
+        const chained = !empty && (isBlockChained(lastDownloadedBlock, { data: blocks[0] }) || isException(blocks[0]));
 
         if (chained) {
             logger.info(
diff --git a/packages/core-blockchain/src/utils/validate-generator.ts b/packages/core-blockchain/src/utils/validate-generator.ts
index af6b19dcab..f517b58948 100644
--- a/packages/core-blockchain/src/utils/validate-generator.ts
+++ b/packages/core-blockchain/src/utils/validate-generator.ts
@@ -1,15 +1,11 @@
 import { app } from "@arkecosystem/core-container";
 import { Logger } from "@arkecosystem/core-interfaces";
-import { isException, models, slots } from "@arkecosystem/crypto";
+import { models, slots } from "@arkecosystem/crypto";
 
 export const validateGenerator = async (block: models.Block): Promise<boolean> => {
     const database = app.resolvePlugin("database");
     const logger = app.resolvePlugin<Logger.ILogger>("logger");
 
-    if (isException(block.data)) {
-        return true;
-    }
-
     const delegates = await database.getActiveDelegates(block.data.height);
     const slot = slots.getSlotNumber(block.data.timestamp);
     const forgingDelegate = delegates[slot % delegates.length];
diff --git a/packages/core-database-postgres/src/repositories/blocks.ts b/packages/core-database-postgres/src/repositories/blocks.ts
index f3ef237914..ce2438442f 100644
--- a/packages/core-database-postgres/src/repositories/blocks.ts
+++ b/packages/core-database-postgres/src/repositories/blocks.ts
@@ -11,7 +11,7 @@ export class BlocksRepository extends Repository {
      * @return {Promise}
      */
     public async findById(id) {
-        return this.db.one(sql.findById, { id });
+        return this.db.oneOrNone(sql.findById, { id });
     }
 
     /**
diff --git a/packages/core-database/src/wallet-manager.ts b/packages/core-database/src/wallet-manager.ts
index 4547cdad50..7c99be1103 100644
--- a/packages/core-database/src/wallet-manager.ts
+++ b/packages/core-database/src/wallet-manager.ts
@@ -1,7 +1,7 @@
 import { app } from "@arkecosystem/core-container";
 import { Logger } from "@arkecosystem/core-interfaces";
 import { roundCalculator } from "@arkecosystem/core-utils";
-import { constants, crypto, formatArktoshi, isException, models } from "@arkecosystem/crypto";
+import { constants, crypto, formatArktoshi, models } from "@arkecosystem/crypto";
 import pluralize from "pluralize";
 
 const { Wallet } = models;
@@ -446,7 +446,7 @@ export class WalletManager {
         }
 
         // handle exceptions / verify that we can apply the transaction to the sender
-        if (isException(data)) {
+        if (transaction.isException) {
             this.logger.warn(`Transaction ${data.id} forcibly applied because it has been added as an exception.`);
         } else if (!sender.canApply(data, errors)) {
             this.logger.error(
diff --git a/packages/crypto/src/crypto/crypto.ts b/packages/crypto/src/crypto/crypto.ts
index 5137202edb..130c5d4043 100644
--- a/packages/crypto/src/crypto/crypto.ts
+++ b/packages/crypto/src/crypto/crypto.ts
@@ -8,7 +8,6 @@ import { Address, KeyPair, Keys, PublicKey, WIF } from "../identities";
 import { configManager } from "../managers";
 import { feeManager } from "../managers";
 import { ITransactionData } from "../models";
-import { INetwork } from "../networks";
 import { Bignum } from "../utils";
 import { HashAlgorithms } from "./hash-algorithms";
 
@@ -25,7 +24,11 @@ class Crypto {
     /**
      * Get the byte representation of the transaction.
      */
-    public getBytes(transaction: ITransactionData, skipSignature: boolean = false, skipSecondSignature: boolean = false): Buffer {
+    public getBytes(
+        transaction: ITransactionData,
+        skipSignature: boolean = false,
+        skipSecondSignature: boolean = false,
+    ): Buffer {
         if (transaction.version && transaction.version !== 1) {
             throw new Error("not supported yet");
         }
@@ -183,7 +186,11 @@ class Crypto {
     /**
      * Get transaction hash.
      */
-    public getHash(transaction: ITransactionData, skipSignature: boolean = false, skipSecondSignature: boolean = false): Buffer {
+    public getHash(
+        transaction: ITransactionData,
+        skipSignature: boolean = false,
+        skipSecondSignature: boolean = false,
+    ): Buffer {
         if (transaction.version && transaction.version !== 1) {
             throw new Error("not supported yet");
         }
diff --git a/packages/crypto/src/models/block.ts b/packages/crypto/src/models/block.ts
index ad79ee636f..fa9cc7d66d 100644
--- a/packages/crypto/src/models/block.ts
+++ b/packages/crypto/src/models/block.ts
@@ -4,7 +4,7 @@ import { crypto, slots } from "../crypto";
 import { BlockDeserializer } from "../deserializers";
 import { configManager } from "../managers/config";
 import { BlockSerializer } from "../serializers";
-import { Bignum } from "../utils";
+import { Bignum, isException } from "../utils";
 import { ITransactionData, Transaction } from "./transaction";
 
 export interface BlockVerification {
@@ -148,6 +148,7 @@ export class Block implements IBlock {
     public data: IBlockData;
     public transactions: Transaction[];
     public verification: BlockVerification;
+    public isException?: boolean;
 
     constructor(data: IBlockData | string) {
         if (typeof data === "string") {
@@ -179,6 +180,9 @@ export class Block implements IBlock {
 
         this.verification = this.verify();
 
+        // Mark Block as exception if id is whitelisted
+        this.isException = isException(this.data);
+
         // order of transactions messed up in mainnet V1
         // TODO: move this to network constants exception using block ids
         if (
diff --git a/packages/crypto/src/models/transaction.ts b/packages/crypto/src/models/transaction.ts
index 888a5dfeb2..9053636c73 100644
--- a/packages/crypto/src/models/transaction.ts
+++ b/packages/crypto/src/models/transaction.ts
@@ -126,6 +126,8 @@ export class Transaction implements ITransactionData {
     public timelock?: any;
     public timelockType?: number;
 
+    public isException?: boolean;
+
     constructor(data: string | ITransactionData) {
         if (typeof data === "string") {
             this.serialized = data;
@@ -134,7 +136,10 @@ export class Transaction implements ITransactionData {
         }
 
         this.data = Transaction.deserialize(this.serialized);
-        this.verified = (this.data.type <= 4 && crypto.verify(this.data)) || isException(this.data);
+        this.verified = this.data.type <= 4 && crypto.verify(this.data);
+
+        // Mark Transaction as exception if id is whitelisted.
+        this.isException = isException(this.data);
 
         // TODO: remove this
         [
@@ -164,7 +169,7 @@ export class Transaction implements ITransactionData {
     }
 
     public verify(): boolean {
-        return this.verified;
+        return this.verified || this.isException;
     }
 
     public toJson(): any {
diff --git a/packages/crypto/src/networks/devnet/exceptions.json b/packages/crypto/src/networks/devnet/exceptions.json
index b186ecbacd..602e90cacb 100644
--- a/packages/crypto/src/networks/devnet/exceptions.json
+++ b/packages/crypto/src/networks/devnet/exceptions.json
@@ -1,5 +1,47 @@
 {
-    "blocks": ["15895730198424359628", "14746174532446639362"],
+    "blocks": [
+        "15895730198424359628",
+        "14746174532446639362",
+        "15249141324902969334",
+        "12360802297474246584",
+        "2565729258675312304",
+        "12614646598841308905",
+        "8274406339991077743",
+        "1661383348822169561",
+        "15467742607784975524",
+        "3665174254391236833",
+        "18033869253067308940",
+        "9121030900295704150",
+        "4296553458016414976",
+        "6837659293375391985",
+        "16540521480028827748",
+        "1485997193168364918",
+        "14159698257459587584",
+        "7561147498738550191",
+        "6247200360319694668",
+        "7363268091423233950",
+        "8738693892321921533",
+        "9014317427571908796",
+        "15519361274991733193",
+        "14013227271822852495",
+        "12603272471546364995",
+        "1944108005996955253",
+        "8469356042757089608",
+        "3433946900869474802",
+        "11257633501887013743",
+        "2997965849869498353",
+        "9196430932294555781",
+        "6730395143580220680",
+        "5806654366498055250",
+        "13290912469992409149",
+        "9502002558776276513",
+        "330791153715252718",
+        "12084096509112875921",
+        "7079194814443264009",
+        "15946707936026547597",
+        "1641736062116508620",
+        "5245034769798442586"
+    ],
     "transactions": [
         "76bd168e57a4431a64617c4e7864df1e0be89831eabaa230e37643efae2def6f",
         "90d06cb306dcc33faba59545e03d91ee83b0409e66a45ffe6a9e3b1049a0c521",

From 12a48e59bd17f6c881200711ed33798333194bd6 Mon Sep 17 00:00:00 2001
From: supaiku <supaiku@protonmail.com>
Date: Wed, 16 Jan 2019 03:29:32 +0100
Subject: [PATCH 3/5] refactor: remove flag again

---
 .../core-blockchain/src/processor/block-processor.ts     | 4 ++--
 packages/core-database/src/wallet-manager.ts             | 4 ++--
 packages/crypto/src/models/block.ts                      | 6 +-----
 packages/crypto/src/models/transaction.ts                | 9 ++-------
 4 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/packages/core-blockchain/src/processor/block-processor.ts b/packages/core-blockchain/src/processor/block-processor.ts
index 47d70f6807..29d51782db 100644
--- a/packages/core-blockchain/src/processor/block-processor.ts
+++ b/packages/core-blockchain/src/processor/block-processor.ts
@@ -2,7 +2,7 @@
 
 import { app } from "@arkecosystem/core-container";
 import { Logger } from "@arkecosystem/core-interfaces";
-import { models } from "@arkecosystem/crypto";
+import { isException, models } from "@arkecosystem/crypto";
 import { Blockchain } from "../blockchain";
 import { isBlockChained } from "../utils/is-block-chained";
 import { validateGenerator } from "../utils/validate-generator";
@@ -36,7 +36,7 @@ export class BlockProcessor {
     }
 
     public async getHandler(block: models.Block): Promise<BlockHandler> {
-        if (block.isException) {
+        if (isException(block.data)) {
             return new ExceptionHandler(this.blockchain, block);
         }
 
diff --git a/packages/core-database/src/wallet-manager.ts b/packages/core-database/src/wallet-manager.ts
index 7c99be1103..4547cdad50 100644
--- a/packages/core-database/src/wallet-manager.ts
+++ b/packages/core-database/src/wallet-manager.ts
@@ -1,7 +1,7 @@
 import { app } from "@arkecosystem/core-container";
 import { Logger } from "@arkecosystem/core-interfaces";
 import { roundCalculator } from "@arkecosystem/core-utils";
-import { constants, crypto, formatArktoshi, models } from "@arkecosystem/crypto";
+import { constants, crypto, formatArktoshi, isException, models } from "@arkecosystem/crypto";
 import pluralize from "pluralize";
 
 const { Wallet } = models;
@@ -446,7 +446,7 @@ export class WalletManager {
         }
 
         // handle exceptions / verify that we can apply the transaction to the sender
-        if (transaction.isException) {
+        if (isException(data)) {
             this.logger.warn(`Transaction ${data.id} forcibly applied because it has been added as an exception.`);
         } else if (!sender.canApply(data, errors)) {
             this.logger.error(
diff --git a/packages/crypto/src/models/block.ts b/packages/crypto/src/models/block.ts
index fa9cc7d66d..ad79ee636f 100644
--- a/packages/crypto/src/models/block.ts
+++ b/packages/crypto/src/models/block.ts
@@ -4,7 +4,7 @@ import { crypto, slots } from "../crypto";
 import { BlockDeserializer } from "../deserializers";
 import { configManager } from "../managers/config";
 import { BlockSerializer } from "../serializers";
-import { Bignum, isException } from "../utils";
+import { Bignum } from "../utils";
 import { ITransactionData, Transaction } from "./transaction";
 
 export interface BlockVerification {
@@ -148,7 +148,6 @@ export class Block implements IBlock {
     public data: IBlockData;
     public transactions: Transaction[];
     public verification: BlockVerification;
-    public isException?: boolean;
 
     constructor(data: IBlockData | string) {
         if (typeof data === "string") {
@@ -180,9 +179,6 @@ export class Block implements IBlock {
 
         this.verification = this.verify();
 
-        // Mark Block as exception if id is whitelisted
-        this.isException = isException(this.data);
-
         // order of transactions messed up in mainnet V1
         // TODO: move this to network constants exception using block ids
         if (
diff --git a/packages/crypto/src/models/transaction.ts b/packages/crypto/src/models/transaction.ts
index 9053636c73..888a5dfeb2 100644
--- a/packages/crypto/src/models/transaction.ts
+++ b/packages/crypto/src/models/transaction.ts
@@ -126,8 +126,6 @@ export class Transaction implements ITransactionData {
     public timelock?: any;
     public timelockType?: number;
 
-    public isException?: boolean;
-
     constructor(data: string | ITransactionData) {
         if (typeof data === "string") {
             this.serialized = data;
@@ -136,10 +134,7 @@ export class Transaction implements ITransactionData {
         }
 
         this.data = Transaction.deserialize(this.serialized);
-        this.verified = this.data.type <= 4 && crypto.verify(this.data);
-
-        // Mark Transaction as exception if id is whitelisted.
-        this.isException = isException(this.data);
+        this.verified = (this.data.type <= 4 && crypto.verify(this.data)) || isException(this.data);
 
         // TODO: remove this
         [
@@ -169,7 +164,7 @@ export class Transaction implements ITransactionData {
     }
 
     public verify(): boolean {
-        return this.verified || this.isException;
+        return this.verified;
     }
 
     public toJson(): any {

From 97b0bf8926f8b2877729d969e65515f98ebed4d6 Mon Sep 17 00:00:00 2001
From: supaiku <supaiku@protonmail.com>
Date: Wed, 16 Jan 2019 03:33:13 +0100
Subject: [PATCH 4/5] refactor: simplify

---
 .../src/processor/handlers/exception-handler.ts                | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/core-blockchain/src/processor/handlers/exception-handler.ts b/packages/core-blockchain/src/processor/handlers/exception-handler.ts
index f40e869f67..52f05e8bec 100644
--- a/packages/core-blockchain/src/processor/handlers/exception-handler.ts
+++ b/packages/core-blockchain/src/processor/handlers/exception-handler.ts
@@ -8,8 +8,7 @@ export class ExceptionHandler extends BlockHandler {
         // block bypasses all other checks.
         const forgedBlock = await this.blockchain.database.getBlock(this.block.data.id);
         if (forgedBlock) {
-            super.execute();
-            return BlockProcessorResult.Rejected;
+            return super.execute();
         }
 
         this.logger.warn(

From ed8a0a8af2fc6144f8f0d3b0e5ecb528789873f8 Mon Sep 17 00:00:00 2001
From: supaiku <supaiku@protonmail.com>
Date: Wed, 16 Jan 2019 03:40:16 +0100
Subject: [PATCH 5/5] misc: typo

---
 packages/core-blockchain/__tests__/blockchain.test.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/core-blockchain/__tests__/blockchain.test.ts b/packages/core-blockchain/__tests__/blockchain.test.ts
index 33036445f0..999665687c 100644
--- a/packages/core-blockchain/__tests__/blockchain.test.ts
+++ b/packages/core-blockchain/__tests__/blockchain.test.ts
@@ -258,7 +258,7 @@ describe("Blockchain", () => {
         });
     });
 
-    describe("handleIncommingBlock", () => {
+    describe("handleIncomingBlock", () => {
         it("should be ok", () => {
             const dispatch = blockchain.dispatch;
             const enqueueBlocks = blockchain.enqueueBlocks;