commit 6908e01492b55252e5c6a59be8b9f9714cb3b362
Author: Joel Pittet <joel@pittet.ca>
Date:   Sun Aug 10 19:24:02 2014 -0700

    test for render array

diff --git a/core/modules/system/src/Tests/Theme/FunctionsTest.php b/core/modules/system/src/Tests/Theme/FunctionsTest.php
index eda48e2..577e075 100644
--- a/core/modules/system/src/Tests/Theme/FunctionsTest.php
+++ b/core/modules/system/src/Tests/Theme/FunctionsTest.php
@@ -55,12 +55,22 @@ function testItemList() {
     $expected = '<div class="item-list"><h3>Some title</h3>No items found.</div>';
     $this->assertThemeOutput('item_list', $variables, $expected, 'Empty %callback generates empty string with title.');
 
-    // Verify that header set to "0" is output.
+    // Verify that title set to 0 is output.
     $variables = array();
     $variables['title'] = 0;
     $variables['empty'] = 'No items found.';
     $expected = '<div class="item-list"><h3>0</h3>No items found.</div>';
-    $this->assertThemeOutput('item_list', $variables, $expected, '%callback with header set to "0" generates a title.');
+    $this->assertThemeOutput('item_list', $variables, $expected, '%callback with title set to 0 generates a title.');
+
+    // Verify that title set to a render array is output.
+    $variables = array();
+    $variables['title'] = array(
+      '#theme' => 'markup',
+      '#markup' => '<span>Render array</span>',
+    );
+    $variables['empty'] = 'No items found.';
+    $expected = '<div class="item-list"><h3><span>Render array</span></h3>No items found.</div>';
+    $this->assertThemeOutput('item_list', $variables, $expected, '%callback with title set to a render array generates a title.');
 
     // Verify that empty text is not displayed when there are list items.
     $variables = array();