bug fix, #12

Author: Changwan Jun

src/Traits/ServerRequestTrait.php

@@ -124,10 +124,10 @@ public function getAttributes()
      */
     public function getAttribute($name, $default = null)
     {
-        if (!isset($this->attributes[$name])) {
-            return $default;
+        if (array_key_exists($name, $this->attributes)) {
+            return $this->attributes[$name];
         }
-        return $this->attributes[$name];
+        return $default;
     }
 
     /**

tests/Issues/Issue12Test.php

@@ -0,0 +1,17 @@
+<?php
+namespace Wandu\Http\Issues;
+
+use Mockery;
+use PHPUnit_Framework_TestCase;
+use Wandu\Http\Psr\ServerRequest;
+
+class Issue12Test extends PHPUnit_Framework_TestCase
+{
+    public function testGetAttribute()
+    {
+        $request = (new ServerRequest())->withAttribute('null', null);
+
+        $this->assertNull($request->getAttribute('null'));
+        $this->assertNull($request->getAttribute('null', 20));
+    }
+}