Ticket #20696: 20696.patch

wp-admin/js/theme.dev.js

@@ -53 +53 @@
  * Displays theme previews on theme install pages.
  */
 jQuery( function($) {
+        if( ! window.postMessage )
+                return;
+
         var preview = $('#theme-installer'),
                 info    = preview.find('.install-theme-info'),
                 panel   = preview.find('.wp-full-overlay-main'),

wp-admin/css/wp-admin.dev.css

@@ -5282 +5282 @@
         bottom: 0;
         left: 0;
         right: 0;
+        height: 100%;
 }
 
 .wp-full-overlay.collapsed,
@@ -5323 +5324 @@
         right: 0;
         top: 0;
         bottom: 0;
+        height: 100%;
 }
 
 .wp-full-overlay.collapsed .wp-full-overlay-main {