Filter through relations prevents duplicate table in query

lib/dialects/abstract/query-generator.js

@@ -569,24 +569,30 @@ module.exports = (function() {
       return dao.tableName + '.' +  attributePart;
     },
 
-    getConditionalJoins: function(options, dao){
+    getConditionalJoins: function(options, originalDao){
       var joins = ''
         , self = this
+        , joinedTables = {}
 
       if (Utils.isHash(options.where)) {
         Object.keys(options.where).forEach(function(filterStr){
           var associationParts = filterStr.split('.')
             , attributePart = associationParts.pop()
+            , dao = originalDao
 
           if (self.isAssociationFilter(filterStr, dao)) {
             associationParts.forEach(function (attribute) {
               var association = self.findAssociation(attribute, dao);
 
+              if(!joinedTables[association.target.tableName]){
+                joinedTables[association.target.tableName] = true;
+
                 if(association.associationType === 'BelongsTo'){
                   joins += ' LEFT JOIN ' + self.quoteIdentifiers(association.target.tableName)
                   joins += ' ON ' + self.quoteIdentifiers(association.source.tableName + '.' + association.identifier)
                   joins += ' = ' + self.quoteIdentifiers(association.target.tableName + '.' + association.target.autoIncrementField)
                 } else if (association.connectorDAO){
+                  joinedTables[association.connectorDAO.tableName] = true;
                   joins += ' LEFT JOIN ' + self.quoteIdentifiers(association.connectorDAO.tableName)
                   joins += ' ON ' + self.quoteIdentifiers(association.source.tableName + '.' + association.source.autoIncrementField)
                   joins += ' = ' + self.quoteIdentifiers(association.connectorDAO.tableName + '.' + association.identifier)
@@ -599,6 +605,7 @@ module.exports = (function() {
                   joins += ' ON ' + self.quoteIdentifiers(association.source.tableName + '.' + association.source.autoIncrementField)
                   joins += ' = ' + self.quoteIdentifiers(association.target.tableName + '.' + association.identifier)
                 }
+              }
               dao = association.target;
             });
           }

test/associations/multiple-level-filters.test.js

@@ -73,6 +73,73 @@ describe(Support.getTestDialectTeaser("Multiple Level Filters"), function() {
     })
   })
 
+  it('avoids duplicated tables in query', function(done) {
+    var User = this.sequelize.define('User', {username: DataTypes.STRING })
+      , Task = this.sequelize.define('Task', {title: DataTypes.STRING })
+      , Project = this.sequelize.define('Project', { title: DataTypes.STRING })
+
+    Project.belongsTo(User);
+    User.hasMany(Project)
+
+    Task.belongsTo(Project);
+    Project.hasMany(Task);
+
+
+    this.sequelize.sync({ force: true }).success(function() {
+      User.bulkCreate([{
+        id: 101,
+        username: 'leia'
+      }, {
+        id: 102,
+        username: 'vader'
+      }]).success(function() {
+        Project.bulkCreate([{
+          id: 201,
+          UserId: 101,
+          title: 'republic'
+        },{
+          id: 202,
+          UserId: 102,
+          title: 'empire'
+        }]).success(function() {
+          Task.bulkCreate([{
+            id: 301,
+            ProjectId: 201,
+            title: 'fight empire'
+          },{
+            id: 302,
+            ProjectId: 201,
+            title: 'stablish republic'
+          },{
+            id: 303,
+            ProjectId: 202,
+            title: 'destroy rebel alliance'
+          },{
+            id: 304,
+            ProjectId: 202,
+            title: 'rule everything'
+          }]).success(function() {
+            Task.findAll({
+              where: {
+                'project.user.username': 'leia',
+                'project.user.id': 101
+              }
+            }).success(function(tasks){
+              try{
+                expect(tasks.length).to.be.equal(2);
+                expect(tasks[0].title).to.be.equal('fight empire');
+                expect(tasks[1].title).to.be.equal('stablish republic');
+                done();
+              }catch(e){
+                done(e);
+              }
+            })
+          });
+        });
+      });
+    })
+  })
+
   it('can filter through hasMany', function(done) {
     var User = this.sequelize.define('User', {username: DataTypes.STRING })
       , Task = this.sequelize.define('Task', {title: DataTypes.STRING })