Issue 5042 - Adds handling for requests which are not associated with browser tab

lib/requestBlocker.js

Index: lib/requestBlocker.js
===================================================================
--- a/lib/requestBlocker.js
+++ b/lib/requestBlocker.js
@@ -64,27 +64,34 @@
       thirdParty, sitekey,
       specificOnly, filter
     );
   }
 }
 
 ext.webRequest.onBeforeRequest.addListener((url, type, page, frame) =>
 {
-  if (checkWhitelisted(page, frame))
-    return true;
-
+  let docDomain = null;
+  let sitekey = null;
+  let specificOnly = false;
+  let thirdParty = false;
   let urlString = stringifyURL(url);
-  let docDomain = extractHostFromFrame(frame);
-  let thirdParty = isThirdParty(url, docDomain);
-  let sitekey = getKey(page, frame);
 
-  let specificOnly = !!checkWhitelisted(
-    page, frame, RegExpFilter.typeMap.GENERICBLOCK
-  );
+
+  if (frame && page)
+  {
+    if (checkWhitelisted(page, frame))
+      return true;
+
+    docDomain = extractHostFromFrame(frame);
+    sitekey = getKey(page, frame);
+    thirdParty = isThirdParty(url, docDomain);
+    specificOnly = !!checkWhitelisted(page, frame,
+                                      RegExpFilter.typeMap.GENERICBLOCK);
+  }
 
   let mappedType = resourceTypes.get(type) || "OTHER";
 
   let filter = defaultMatcher.matchesAny(
     urlString, RegExpFilter.typeMap[mappedType],
     docDomain, thirdParty, sitekey, specificOnly
   );