fix regression introduced in OpenMage#2993 where attributes are not correctly pre-filtered for the layered navigation

Author: davidhiendl

app/code/core/Mage/Catalog/Model/Layer.php

@@ -212,6 +212,7 @@ public function getFilterableAttributes()
             foreach ($setAttributeIds as $attributeId) {
                 if (!isset($attributes[$attributeId])) {
                     $attribute = $eavConfig->getAttribute(Mage_Catalog_Model_Product::ENTITY, $attributeId);
+                    if (!$this->_filterFilterableAttributes($attribute)) continue;
                     if ($attribute instanceof Mage_Catalog_Model_Resource_Eav_Attribute && $attribute->getIsFilterable()) {
                         $attributes[$attributeId] = $attribute;
                     }
@@ -249,6 +250,17 @@ protected function _prepareAttributeCollection($collection)
         return $collection;
     }
 
+    /**
+     * Filter which attributes are included in getFilterableAttributes
+     *
+     * @param Mage_Catalog_Model_Resource_Eav_Attribute $attribute
+     * @return  bool
+     */
+    protected function _filterFilterableAttributes($attribute)
+    {
+        return $attribute->getIsFilterable() > 0;
+    }
+
     /**
      * Retrieve layer state object
      *

app/code/core/Mage/CatalogSearch/Model/Layer.php

@@ -99,6 +99,17 @@ protected function _prepareAttributeCollection($collection)
         return $collection;
     }
 
+    /**
+     * Filter which attributes are included in getFilterableAttributes
+     *
+     * @param Mage_Catalog_Model_Resource_Eav_Attribute $attribute
+     * @return  bool
+     */
+    protected function _filterFilterableAttributes($attribute)
+    {
+        return $attribute->getIsVisible() && $attribute->getIsFilterableInSearch() > 0;
+    }
+
     /**
      * Prepare attribute for use in layered navigation
      *