diff --git a/tests/UnitTests/TemplateSource/ValueTests/PHPfunctions/PhpFunctionTest.php b/tests/UnitTests/TemplateSource/ValueTests/PHPfunctions/PhpFunctionTest.php
index 8892a542..43913d66 100644
--- a/tests/UnitTests/TemplateSource/ValueTests/PHPfunctions/PhpFunctionTest.php
+++ b/tests/UnitTests/TemplateSource/ValueTests/PHPfunctions/PhpFunctionTest.php
@@ -156,6 +156,57 @@ class PhpFunctionTest extends PHPUnit_Smarty
         ,{if isset($var->pass(1))} true {else} false {/IF}
         '));
     }
+
+    /**
+     * test PHP isset() on (non-)variables
+     * @dataProvider        dataTestIsset3
+     * @param string $strTemplate template to test
+     * @param string $result expected result
+     */
+    public function testIsset3($strTemplate, $result)
+    {
+        $this->smarty->disableSecurity();
+
+        $this->smarty->assign('varobject', new TestIsset());
+        $this->smarty->assign('vararray', $vararray = [
+            'keythatexists' => false,
+            'keywitharray' => [1 => 1],
+            'keywithobject' => new TestIsset()]
+        );
+
+        $this->smarty->assign('key', 'A');
+        $this->smarty->assign('_varsimpleA', 1);
+        $this->smarty->assign('varsimpleB', 0);
+        $this->smarty->assign('varsimpleC', null);
+
+        $this->assertEquals($result, $this->smarty->fetch('string:' . $strTemplate));
+    }
+
+    /**
+     * Data provider for testIsset3
+     */
+    public function dataTestIsset3()
+    {
+        return array(
+            array('{if isset($varobject->arr)}true{else}false{/if}', 'true'),
+            array('{if isset($vararray["keywitharray"])}true{else}false{/if}', 'true'),
+            array('{if isset($vararray["keythatexists"])}true{else}false{/if}', 'true'),
+            array('{if isset($vararray["nonexistingkey"])}true{else}false{/if}', 'false'),
+            array('{if isset($_GET["sscr6hr6cz34j6"])}true{else}false{/if}', 'false'),
+            array('{if isset(count([\'hi\']))}true{else}false{/if}', 'true'),
+            array('{if isset($vararray[\'keywitharray\'][intval(\'1\')])}true{else}false{/if}', 'true'),
+            array('{if isset($vararray[\'keywithobject\']->arr[\'isSet\'])}true{else}false{/if}', 'true'),
+            array('{if isset($vararray[\'keywithobject\']->arr[\'isNull\'])}true{else}false{/if}', 'false'),
+            array('{if isset($varobject->arr[\'isSet\'])}true{else}false{/if}', 'true'),
+            array('{if isset($varobject->arr[\'isNull\'])}true{else}false{/if}', 'false'),
+            array('{if isset($_varsimpleA)}true{else}false{/if}', 'true'),
+            array('{if isset($varsimpleB)}true{else}false{/if}', 'true'),
+            array('{if isset($varsimpleC)}true{else}false{/if}', 'false'),
+            array('{if isset($_varsimpleA && varsimpleB)}true{else}false{/if}', 'true'),
+            array('{if isset($_varsimpleA && varsimpleC)}true{else}false{/if}', 'true'),
+            array('{if isset($_varsimple{$key})}true{else}false{/if}', 'true'),
+        );
+    }
 }
 
 /**