Issue 4485 - Clear cache directory

src/org/adblockplus/sbrowser/contentblocker/engine/Engine.java

Index: src/org/adblockplus/sbrowser/contentblocker/engine/Engine.java
===================================================================
--- a/src/org/adblockplus/sbrowser/contentblocker/engine/Engine.java
+++ b/src/org/adblockplus/sbrowser/contentblocker/engine/Engine.java
@@ -249,16 +249,30 @@ public final class Engine
     {
       Log.d(TAG, "Writing filters...");
       final File filterFile = this.subscriptions.createAndWriteFile();
 
       final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this.serviceContext);
       final String key = this.serviceContext.getString(R.string.key_cached_filter_path);
       prefs.edit().putString(key, filterFile.getAbsolutePath()).commit();
 
+      Log.d(TAG, "Cleaning up cache...");
+      final File dummyFile = getDummyFilterFile(this.serviceContext);
+      final File[] cacheDirFiles = getFilterCacheDir(this.serviceContext).listFiles();
+      if (cacheDirFiles != null)
+      {
+        for (final File file : cacheDirFiles)
+        {
+          if (!file.equals(dummyFile) && !file.equals(filterFile))
+          {
+            Log.d(TAG, "Deleting file:" + file);
+            file.delete();
+          }
+        }
+      }
     }
     catch (IOException e)
     {
       Log.e(TAG, "Failed to write filters", e);
     }
     finally
     {
       this.unlock();