Fix(#4953) : Added failing test

changelog.md

+# Future
+- [FIXED] MySQL throws error when null GEOMETRY data results in empty buffer [#4953](https://github.com/sequelize/sequelize/issues/4953)
+
 # 3.16.0
 # 3.16.0
 - [ADDED] PostgreSQL tsrange (Range of timestamp without time zone) data type support.
 - [ADDED] PostgreSQL tsrange (Range of timestamp without time zone) data type support.
 - [ADDED] hasOne scope support [#5113](https://github.com/sequelize/sequelize/pull/5113)
 - [ADDED] hasOne scope support [#5113](https://github.com/sequelize/sequelize/pull/5113)
 - [FIXED] attributes from multiple scopes does not merge  [#4856](https://github.com/sequelize/sequelize/issues/4856)
 - [FIXED] attributes from multiple scopes does not merge  [#4856](https://github.com/sequelize/sequelize/issues/4856)
 - [FIXED] Support Unicode strings in mssql [#3752](https://github.com/sequelize/sequelize/issues/3752)
 - [FIXED] Support Unicode strings in mssql [#3752](https://github.com/sequelize/sequelize/issues/3752)
 - [FIXED] Do not inject include twice in `options.include` [#5106](https://github.com/sequelize/sequelize/pull/5106)
 - [FIXED] Do not inject include twice in `options.include` [#5106](https://github.com/sequelize/sequelize/pull/5106)
-- [FIXED] Expand and validate include in `aggregate` [#5106](https://github.com/sequelize/sequelize/pull/5106)
+- [FIXED] Expand and validate include in `aggregate`
 
 
 # 3.15.1
 # 3.15.1
 - [FIXED] calling Model.update() modifies passed values  [#4520](https://github.com/sequelize/sequelize/issues/4520)
 - [FIXED] calling Model.update() modifies passed values  [#4520](https://github.com/sequelize/sequelize/issues/4520)

lib/dialects/mysql/data-types.js

@@ -60,8 +60,13 @@ module.exports = function (BaseTypes) {
   });
   });
 
 
   GEOMETRY.parse = GEOMETRY.prototype.parse = function(value) {
   GEOMETRY.parse = GEOMETRY.prototype.parse = function(value) {
+    value = value.buffer();
+    if (value === null) {
+       return null;
+    }
+
     // For some reason, discard the first 4 bytes
     // For some reason, discard the first 4 bytes
-    value = value.buffer().slice(4);
+    value = value.slice(4);
 
 
     return wkx.Geometry.parse(value).toGeoJSON();
     return wkx.Geometry.parse(value).toGeoJSON();
   };
   };

test/integration/data-types.test.js

@@ -273,4 +273,28 @@ describe(Support.getTestDialectTeaser('DataTypes'), function() {
      // No dialects actually allow us to identify that we get an enum back..
      // No dialects actually allow us to identify that we get an enum back..
     testFailure(Type);
     testFailure(Type);
   });
   });
+
+  it('should parse an empty GEOMETRY field', function () {
+   var Type = new Sequelize.GEOMETRY();
+
+   if (current.dialect.supports.GEOMETRY) {
+     current.refreshTypes();
+
+     var User = current.define('user', { field: Type }, { timestamps: false });
+     var point = { type: "Point", coordinates: [] };
+
+     return current.sync({ force: true }).then(function () {
+       return User.create({
+          //insert a null GEOMETRY type
+          field: point
+        });
+      }).then(function () {
+        //This case throw unhandled exception
+        return User.findAll();
+      }).then(function(users){
+        //it contains the null GEOMETRY data
+        expect(users[0].field).to.be.null;
+      });
+   }
+ });
 });
 });