Fix stray protocol packet errors to be catchable

fixes mysqljs#867

Author: dougwilson

Changes.md

@@ -6,6 +6,7 @@ you spot any mistakes.
 
 ## HEAD
 
+* Fix stray protocol packet errors to be catchable #867
 * Fix timing of fatal protocol errors bubbling to user #879
 
 ## v2.4.1 (2014-07-17)

lib/protocol/Protocol.js

@@ -221,8 +221,18 @@ Protocol.prototype._validateEnqueue = function(sequence) {
 
 Protocol.prototype._parsePacket = function() {
   var sequence = this._queue[0];
-  var Packet   = this._determinePacket(sequence);
-  var packet   = new Packet({
+
+  if (!sequence) {
+    var err   = new Error('Received packet with no active sequence.');
+    err.code  = 'PROTOCOL_STRAY_PACKET';
+    err.fatal = true;
+
+    this._delegateError(err);
+    return;
+  }
+
+  var Packet = this._determinePacket(sequence);
+  var packet = new Packet({
     protocol41: this._config.protocol41
   });
 

test/unit/connection/test-protocol-stray-packet.js

@@ -0,0 +1,33 @@
+var assert     = require('assert');
+var common     = require('../../common');
+var connection = common.createConnection({port: common.fakeServerPort});
+var server     = common.createFakeServer();
+
+server.listen(common.fakeServerPort, function (err) {
+  assert.ifError(err);
+
+  connection.on('error', function (err) {
+    assert.equal(err.code, 'PROTOCOL_STRAY_PACKET');
+    assert.equal(err.fatal, true);
+    connection.destroy();
+    server.destroy();
+  });
+
+  connection.query('SELECT 1', assert.ifError);
+});
+
+server.on('connection', function(conn) {
+  conn.handshake();
+  conn.on('query', function(packet) {
+    var resetPacketNumber = this._parser.resetPacketNumber;
+
+    // Prevent packet number from being reset
+    this._parser.resetPacketNumber = function () {};
+    this._handleQueryPacket(packet);
+
+    this._parser.resetPacketNumber = resetPacketNumber;
+    this._sendPacket(new common.Packets.ResultSetHeaderPacket({
+      fieldCount: 1
+    }));
+  });
+});

test/unit/pool/test-protocol-stray-packet.js

@@ -0,0 +1,49 @@
+var assert     = require('assert');
+var common     = require('../../common');
+var pool       = common.createPool({port: common.fakeServerPort});
+var server     = common.createFakeServer();
+
+var connCount = 0;
+
+server.listen(common.fakeServerPort, function (err) {
+  assert.ifError(err);
+
+  pool.on('error', function (err) {
+    assert.equal(err.code, 'PROTOCOL_STRAY_PACKET');
+    assert.equal(err.fatal, true);
+    connection.destroy();
+    server.destroy();
+  });
+
+  pool.query('SELECT 1', function (err) {
+    assert.ifError(err);
+
+    pool.getConnection(function (err) {
+      assert.ifError(err);
+      assert.equal(connCount, 2);
+
+      pool.end(function (err) {
+        assert.ifError(err);
+        server.destroy();
+      });
+    });
+  });
+});
+
+server.on('connection', function (conn) {
+  connCount++;
+  conn.handshake();
+  conn.on('query', function(packet) {
+    var resetPacketNumber = this._parser.resetPacketNumber;
+
+    // Prevent packet number from being reset
+    this._parser.resetPacketNumber = function () {};
+    this._handleQueryPacket(packet);
+
+    this._parser.resetPacketNumber = resetPacketNumber;
+    this._sendPacket(new common.Packets.ResultSetHeaderPacket({
+      fieldCount: 1
+    }));
+    this._parser.resetPacketNumber();
+  });
+});