Caching: Altered purifier cache folder to be server-created

Moved from a static folder to a dynamically created folder in the
framework/cache directory, to increase the chance that it's created with
server-writable permissions.
This is due to an issue where users had permission issues, since adding
a new folder means it's created by the git user and often
non-web-writable.

Author: ssddanbrown

app/Util/ConfiguredHtmlPurifier.php

@@ -22,8 +22,13 @@ class ConfiguredHtmlPurifier
 
     public function __construct()
     {
+        // This is done by the web-server at run-time, with the existing
+        // storage/framework/cache folder to ensure we're using a server-writable folder.
+        $cachePath = storage_path('framework/cache/purifier');
+        $this->createCacheFolderIfNeeded($cachePath);
+
         $config = HTMLPurifier_HTML5Config::createDefault();
-        $this->setConfig($config);
+        $this->setConfig($config, $cachePath);
         $this->resetCacheIfNeeded($config);
 
         $htmlDef = $config->getDefinition('HTML', true, true);
@@ -34,6 +39,13 @@ public function __construct()
         $this->purifier = new HTMLPurifier($config);
     }
 
+    protected function createCacheFolderIfNeeded(string $cachePath): void
+    {
+        if (!file_exists($cachePath)) {
+            mkdir($cachePath, 0777, true);
+        }
+    }
+
     protected function resetCacheIfNeeded(HTMLPurifier_Config $config): void
     {
         if (self::$cachedChecked) {
@@ -53,9 +65,9 @@ protected function resetCacheIfNeeded(HTMLPurifier_Config $config): void
         self::$cachedChecked = true;
     }
 
-    protected function setConfig(HTMLPurifier_Config $config): void
+    protected function setConfig(HTMLPurifier_Config $config, string $cachePath): void
     {
-        $config->set('Cache.SerializerPath', storage_path('framework/purifier'));
+        $config->set('Cache.SerializerPath', $cachePath);
         $config->set('Core.AllowHostnameUnderscore', true);
         $config->set('CSS.AllowTricky', true);
         $config->set('HTML.SafeIframe', true);