Issue 4327 - Prevent generic document blocking

lib/abp2blocklist.js

Index: lib/abp2blocklist.js
diff --git a/lib/abp2blocklist.js b/lib/abp2blocklist.js
index c86cb9d4b55725a8a44399bb853bcab7381d4521..4ac4453a010ad7ec0f1585b89d3dee6d1b9dab2d 100644
--- a/lib/abp2blocklist.js
+++ b/lib/abp2blocklist.js
@@ -276,6 +276,17 @@ function convertFilterAddRules(rules, filter, action, withResourceTypes)
   {
     trigger["resource-type"] = getResourceTypes(filter);
 
+    // Content Blocking rules can't differentiate between sub-document
+    // requests (iframes) and top-level document requests (redirects). So to
+    // avoid too many false-positives we stop generic rules (no hostname part)
+    // from blocking document requests.
+    if (action == "block" && !parsed.hostname)
+    {
+      let documentIndex = trigger["resource-type"].indexOf("document");
+      if (documentIndex > -1)
+        trigger["resource-type"].splice(documentIndex, 1);
+    }
+
     // Rules with no resource types to match shouldn't match anything and
     // therefore shouldn't be created.
     if (trigger["resource-type"].length == 0)