Issue 3624 - Filter list height is too small by default if Vertical Layout is enabled

lib/main.js

 /*
  * This Source Code is subject to the terms of the Mozilla Public License
  * version 2.0 (the "License"). You can obtain a copy of the License at
  * http://mozilla.org/MPL/2.0/.
  */
 
 Cu.import("resource://gre/modules/Services.jsm");
 
 let {Prefs} = require("prefs");
 let {WindowObserver} = require("windowObserver");
@@ skipping 39 matching lines @@
 
 var VerticalPreferencesLayout =
 {
   __proto__: WindowFeature,
   windowUrl: "chrome://adblockplus/content/ui/filters.xul",
 
   _applyToWindow: function(window)
   {
     let content = window.document.getElementById("content");
     let splitter = window.document.getElementById("filtersSplitter");
-    if (!content || !splitter)
+    let tree = window.document.getElementById("filtersTree");
+    if (!content || !splitter || !tree)
       return;
 
     content.setAttribute("orient", "vertical");
     splitter.setAttribute("orient", "vertical");
+    tree.setAttribute("minheight", "60px");
   },
 
   _removeFromWindow: function(window)
   {
     let content = window.document.getElementById("content");
     let splitter = window.document.getElementById("filtersSplitter");
-    if (!content || !splitter)
+    let tree = window.document.getElementById("filtersTree");
+    if (!content || !splitter || !tree)
       return;
 
     content.removeAttribute("orient");
     splitter.setAttribute("orient", "horizontal");
+    tree.removeAttribute("minheight");
   }
 };
 
 var StylesheetFeature =
 {
   uri: null,
   stylesheetService: Cc["@mozilla.org/content/style-sheet-service;1"].getService(Ci.nsIStyleSheetService),
 
   init: function()
   {
@@ skipping 125 matching lines @@
     else
       features[name].shutdown();
   }
 }
 
 // Initialize features and make sure to update them on changes
 for (let feature in features)
   updateFeature(feature);
 
 Prefs.addListener(updateFeature);