Noissue - Avoid loop if DevTools is closed

lib/hitLogger.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 71 matching lines @@
  *   Whether the origin of the request and document differs
  * @param {?string} request.sitekey
  *   The active sitekey if there is any
  * @param {?boolean} request.specificOnly
  *   Whether generic filters should be ignored
  * @param {?BlockingFilter} filter
  *  The matched filter or null if there is no match
  */
 exports.logRequest = (tabIds, request, filter) =>
 {
-  for (let tabId of tabIds)
-    eventEmitter.emit(tabId, request, filter);
+  if (eventEmitter.hasListeners())
+  {
+    for (let tabId of tabIds)
+      eventEmitter.emit(tabId, request, filter);
+  }
 };
 
 /**
  * Logs active element hiding filters for a tab.
  *
  * @param {number}   tabId      The ID of the tab, the elements were hidden in
  * @param {string[]} selectors  The selectors of applied ElemHideFilters
  * @param {string[]} filters    The text of applied ElemHideEmulationFilters
  * @param {string}   docDomain  The hostname of the document
  */
@@ skipping 46 matching lines @@
   }
 };
 
 port.on("hitLogger.traceElemHide", (message, sender) =>
 {
   logHiddenElements(
     sender.page.id, message.selectors, message.filters,
     extractHostFromFrame(sender.frame)
   );
 });