Prevent crashing the application when a block is received and node is syncing or forging - Closes #3896

framework/src/modules/chain/blocks/blocks.js

@@ -313,7 +313,12 @@ class Blocks extends EventEmitter {
 	// Process a block from the P2P
 	async receiveBlockFromNetwork(block) {
 		return this.sequence.add(async () => {
-			this._shouldNotBeActive();
+			if (this._isActive) {
+				this.logger.info(
+					'Ignoring received block from network, node is syncing or forging'
+				);
+				return;
+			}
 			this._isActive = true;
 			// set active to true
 			if (this.blocksVerify.isSaneBlock(block, this._lastBlock)) {

framework/test/mocha/unit/modules/chain/blocks/blocks.js

@@ -340,6 +340,29 @@ describe('blocks', () => {
 				});
 			});
 		});
+		describe('client not ready to receive block', () => {
+			beforeEach(async () => {
+				sinonSandbox.stub(blocksInstance.blocksVerify, 'isSaneBlock');
+				sequenceStub.add.callsFake(async fn => {
+					await fn();
+				});
+			});
+
+			it('should not process the received block and info log it', async () => {
+				blocksInstance._isActive = true;
+				await blocksInstance.receiveBlockFromNetwork({
+					id: '2',
+					previousBlock: '1',
+					height: 2,
+				});
+
+				expect(loggerStub.info).to.be.calledWith(
+					'Ignoring received block from network, node is syncing or forging'
+				);
+				expect(blocksInstance._isActive).to.be.true; // Value shouldn't be altered.
+				expect(blocksInstance.blocksVerify.isSaneBlock).to.not.be.called;
+			});
+		});
 	});
 
 	describe('_rebuildMode', () => {