fix transaction with dropBufferSupport:true (#314)

Closes #313

Author: shaharmor

lib/pipeline.js

@@ -190,6 +190,7 @@ Pipeline.prototype.multi = function () {
 };
 
 var execBuffer = Pipeline.prototype.execBuffer;
+var exec = Pipeline.prototype.exec;
 Pipeline.prototype.execBuffer = util.deprecate(function () {
   if (this._transactions > 0) {
     this._transactions -= 1;
@@ -200,7 +201,7 @@ Pipeline.prototype.execBuffer = util.deprecate(function () {
 Pipeline.prototype.exec = function (callback) {
   if (this._transactions > 0) {
     this._transactions -= 1;
-    return execBuffer.apply(this, arguments);
+    return (this.options.dropBufferSupport ? exec : execBuffer).apply(this, arguments);
   }
   if (!this.nodeifiedPromise) {
     this.nodeifiedPromise = true;

test/functional/drop_buffer_support.js

@@ -84,16 +84,44 @@ describe('dropBufferSupport', function () {
         expect(err).to.eql(null);
         expect(res[0][1]).to.eql('OK');
         expect(res[1][1]).to.eql('bar');
+        redis.disconnect();
         done();
       });
     });
 
+    it('should work with transaction', function (done) {
+      var redis = new Redis({ dropBufferSupport: true });
+      redis.multi()
+        .set('foo', 'bar')
+        .get('foo')
+        .exec(function(err, res) {
+          expect(err).to.eql(null);
+          expect(res[0][1]).to.eql('OK');
+          expect(res[1][1]).to.eql('bar');
+          redis.disconnect();
+          done();
+        });
+    });
+
+    it('should fail early with Buffer transaction', function (done) {
+      var redis = new Redis({ dropBufferSupport: true });
+      redis.multi()
+        .set('foo', 'bar')
+        .getBuffer(new Buffer('foo'), function(err) {
+          expect(err.message).to.match(/Buffer methods are not available/);
+          redis.disconnect();
+          done();
+        });
+    });
+
     it('should work with internal select command', function (done) {
       var redis = new Redis({ dropBufferSupport: true, db: 1 });
       var check = new Redis({ db: 1 });
       redis.set('foo', 'bar', function () {
         check.get('foo', function (err, res) {
           expect(res).to.eql('bar');
+          redis.disconnect();
+          check.disconnect();
           done();
         });
       });