Index: js/navigation.js
===================================================================
--- phpMyAdmin-4.8.4-all-languages/js/navigation.js
+++ phpMyAdmin-4.8.4-all-languages/js/navigation.js	2018-10-26 14:48:19.910954878 +0200
@@ -1270,9 +1270,11 @@
         var $nav_tree   = $('#pma_navigation_tree');
         var $nav_header = $('#pma_navigation_header');
         var $nav_tree_content = $('#pma_navigation_tree_content');
-        $nav_tree.height($nav.height() - $nav_header.height());
+        var height = ($nav.height() - $nav_header.height());
+        height = height > 50 ? height : 800; //keep min. height
+        $nav_tree.height(height);
         if ($nav_tree_content.length > 0) {
-            $nav_tree_content.height($nav_tree.height() - $nav_tree_content.position().top);
+            $nav_tree_content.height(height - $nav_tree_content.position().top);
         } else {
             // TODO: in fast filter search response there is no #pma_navigation_tree_content, needs to be added in php
             $nav_tree.css({