Add testcase to test connection hang ups when a query is issued 100 ms after the…

… last one (right when the client connection is closing)
Also added a possible fix

lib/dialects/mysql/connector-manager.js

@@ -225,9 +225,7 @@ module.exports = (function() {
 
 
   var disconnect = function(client) {
   var disconnect = function(client) {
     var self = this;
     var self = this;
-    if (!this.useQueue) {
     this.client = null;
     this.client = null;
-    }
 
 
     client.end(function() {
     client.end(function() {
       if (!self.useQueue) {
       if (!self.useQueue) {
@@ -238,14 +236,11 @@ module.exports = (function() {
       var cleanup = function () {
       var cleanup = function () {
         var retryCt = 0
         var retryCt = 0
         // make sure to let client finish before calling destroy
         // make sure to let client finish before calling destroy
-        if (self && self.hasQueuedItems) {
+        if (client._queue && (client._queue.length > 0)) {
           return
           return
         }
         }
         // needed to prevent mysql connection leak
         // needed to prevent mysql connection leak
         client.destroy()
         client.destroy()
-        if (self && self.client) {
-          self.client = null
-        }
         clearInterval(intervalObj)
         clearInterval(intervalObj)
       }
       }
       intervalObj = setInterval(cleanup, 10)
       intervalObj = setInterval(cleanup, 10)

test/mysql/connector-manager.test.js

@@ -32,5 +32,26 @@ if (Support.dialectIsMySQL()) {
         })
         })
       })
       })
     })
     })
+
+    it('accepts new queries after shutting down a connection', function(done) {
+      // Create a sequelize instance with pooling disabled
+      var sequelize = Support.createSequelizeInstance({ pool: false })
+      var User = sequelize.define('User', { username: DataTypes.STRING })
+
+      User.sync({force: true}).on('success', function() {
+        User.create({username: 'user1'}).on('success', function() {
+          // After 100 ms the DB connection will be disconnected for inactivity
+          setTimeout(function() {
+            // This query will be queued just after the `client.end` is executed and before its callback is called
+            sequelize.query('SELECT COUNT(*) AS count FROM Users').on('success', function(count) {
+              expect(count[0].count).to.equal(1)
+              done()
+            }).error(function(error) {
+              expect(error).to.not.exist
+            })
+          }, 100)
+        })
+      })
+    })
   })
   })
 }
 }

test/support.js

@@ -45,7 +45,7 @@ var Support = {
     var config = Config[options.dialect]
     var config = Config[options.dialect]
 
 
     options.logging = (options.hasOwnProperty('logging') ? options.logging : false)
     options.logging = (options.hasOwnProperty('logging') ? options.logging : false)
-    options.pool    = options.pool || config.pool
+    options.pool    = options.pool !== undefined ? options.pool : config.pool
 
 
     var sequelizeOptions = {
     var sequelizeOptions = {
       host:           options.host || config.host,
       host:           options.host || config.host,