Simplify some filtering stuff, do not unescape empty strings.

src/librssguard/core/feeddownloader.cpp

@@ -113,18 +113,13 @@ void FeedDownloader::updateOneFeed(Feed* feed) {
     // Perform per-message filtering.
     QJSEngine filter_engine;
 
-    MessageFilter::initializeFilteringEngine(filter_engine);
-
     // Create JavaScript communication wrapper for the message.
     MessageObject msg_obj(&database,
                           feed->customId(),
                           feed->getParentServiceRoot()->accountId(),
                           feed->getParentServiceRoot()->labelsNode()->labels());
 
-    // Register the wrapper.
+    MessageFilter::initializeFilteringEngine(filter_engine, &msg_obj);
-    auto js_object = filter_engine.newQObject(&msg_obj);
-
-    filter_engine.globalObject().setProperty("msg", js_object);
 
     qDebugNN << LOGSEC_FEEDDOWNLOADER << "Setting up JS evaluation took " << tmr.nsecsElapsed() / 1000 << " microseconds.";
 

src/librssguard/core/messagefilter.cpp

@@ -79,10 +79,15 @@ void MessageFilter::setScript(const QString& script) {
   m_script = script;
 }
 
-void MessageFilter::initializeFilteringEngine(QJSEngine& engine) {
+void MessageFilter::initializeFilteringEngine(QJSEngine& engine, MessageObject* message_wrapper) {
   engine.installExtensions(QJSEngine::Extension::ConsoleExtension);
   engine.globalObject().setProperty("MSG_ACCEPT", int(FilteringAction::Accept));
   engine.globalObject().setProperty("MSG_IGNORE", int(FilteringAction::Ignore));
+
+  // Register the wrapper.
+  auto js_object = engine.newQObject(message_wrapper);
+
+  engine.globalObject().setProperty("msg", js_object);
 }
 
 void MessageFilter::setId(int id) {

src/librssguard/core/messagefilter.h

@@ -27,7 +27,7 @@ class MessageFilter : public QObject {
     QString script() const;
     void setScript(const QString& script);
 
-    static void initializeFilteringEngine(QJSEngine& engine);
+    static void initializeFilteringEngine(QJSEngine& engine, MessageObject* message_wrapper);
 
   private:
     int m_id;

src/librssguard/gui/dialogs/formmessagefiltersmanager.cpp

@@ -147,24 +147,14 @@ void FormMessageFiltersManager::loadFilter() {
 void FormMessageFiltersManager::testFilter() {
   // Perform per-message filtering.
   QJSEngine filter_engine;
-
-  MessageFilter::initializeFilteringEngine(filter_engine);
-
   QSqlDatabase database = qApp->database()->connection(metaObject()->className());
-
-  // Create JavaScript communication wrapper for the message.
   MessageObject msg_obj(&database, QString::number(NO_PARENT_CATEGORY), NO_PARENT_CATEGORY, {});
-
+  auto* fltr = selectedFilter();
-  // Register the wrapper.
-  auto js_object = filter_engine.newQObject(&msg_obj);
-
-  filter_engine.globalObject().setProperty("msg", js_object);
-
   Message msg = testingMessage();
 
-  msg_obj.setMessage(&msg);
+  MessageFilter::initializeFilteringEngine(filter_engine, &msg_obj);
 
-  auto* fltr = selectedFilter();
+  msg_obj.setMessage(&msg);
 
   try {
     FilteringAction decision = fltr->filterMessage(&filter_engine);

src/librssguard/network-web/webfactory.cpp

@@ -70,6 +70,10 @@ QString WebFactory::stripTags(QString text) {
 }
 
 QString WebFactory::unescapeHtml(const QString& html) {
+  if (html.isEmpty()) {
+    return html;
+  }
+
   if (m_htmlNamedEntities.isEmpty()) {
     generateUnescapes();
   }