Issue #2068217 by thedavidmeister: Fixed array('hook') syntax for suggestions...

Issue #2068217 by thedavidmeister: Fixed array('hook') syntax for suggestions is broken for #theme_wrappers().

core/includes/common.inc

@@ -3916,7 +3916,7 @@ function drupal_render(&$elements) {
       // only this theme() call. This allows #theme hooks and #theme_wrappers
       // hooks to share variable names without conflict or ambiguity.
       $wrapper_elements = $elements;
-      if (is_array($value)) {
+      if (is_string($key)) {
         $wrapper_hook = $key;
         foreach ($value as $attribute => $override) {
           $wrapper_elements[$attribute] = $override;

core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php

@@ -134,6 +134,15 @@ function testDrupalRenderBasics() {
         ),
         'expected' => '<div class="foo"><div class="bar"></div></div>',
       ),
+      // Array syntax theme hook suggestion in #theme_wrappers.
+      array(
+        'name' => '#theme_wrappers implements an array style theme hook suggestion',
+        'value' => array(
+          '#theme_wrappers' => array(array('container')),
+          '#attributes' => array('class' => 'foo'),
+        ),
+        'expected' => '<div class="foo"></div>',
+      ),
 
       // Test handling of #markup as a fallback for #theme hooks.
       // Simple #markup with no theme.