Merge pull request #2485 from overlookmotel/bug-fix-quote

Fix(queryGenerator#quote): `as` variable

lib/dialects/abstract/query-generator.js

@@ -536,24 +536,27 @@ module.exports = (function() {
         // (checking associations to see if names should be singularised or not)
         var tableNames = []
           , parentAssociation
-          , len = obj.length;
+          , len = obj.length
+          , item
+          , model
+          , as
+          , association;
         for (var i = 0; i < len - 1; i++) {
-          var item = obj[i];
+          item = obj[i];
           if (item._modelAttribute || Utils._.isString(item) || item._isSequelizeMethod || 'raw' in item) {
             break;
           }
 
-          var model, as;
           if (item instanceof Model) {
             model = item;
+            as = undefined;
           } else {
             model = item.model;
             as = item.as;
           }
 
           // check if model provided is through table
-          var association;
-          if (!as && parentAssociation && parentAssociation.through.model === model) {
+          if (!as && parentAssociation && parentAssociation.through && parentAssociation.through.model === model) {
             association = {as: Utils.singularize(model.tableName, model.options.language)};
           } else {
             // find applicable association for linking parent to this model