From 83d028ac7d974ff264e3f8d67c2f1e2237dabcb3 Mon Sep 17 00:00:00 2001
From: Raymond Hill <rhill@raymondhill.net>
Date: Mon, 25 Apr 2022 09:49:31 -0400
Subject: [PATCH] Report specific filter before generic one

Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/2092

Regression from:
- https://github.com/gorhill/uBlock/commit/72bb89495ba0928042b8c0fe22ee57f6e955ca90
---
 src/js/messaging.js            |  2 +-
 src/js/reverselookup-worker.js | 49 +++++++++++++++-------------------
 src/js/reverselookup.js        |  6 ++---
 3 files changed, 26 insertions(+), 31 deletions(-)

diff --git a/src/js/messaging.js b/src/js/messaging.js
index 6feb12c7c..ce210c9f3 100644
--- a/src/js/messaging.js
+++ b/src/js/messaging.js
@@ -118,7 +118,7 @@ const onMessage = function(request, sender, callback) {
         return;
 
     case 'listsFromCosmeticFilter':
-        staticFilteringReverseLookup.fromCosmeticFilter(
+        staticFilteringReverseLookup.fromExtendedFilter(
             request
         ).then(response => {
             callback(response);
diff --git a/src/js/reverselookup-worker.js b/src/js/reverselookup-worker.js
index eb20e3005..48ea97498 100644
--- a/src/js/reverselookup-worker.js
+++ b/src/js/reverselookup-worker.js
@@ -23,31 +23,28 @@
 
 /******************************************************************************/
 
-{
-// >>>>> start of local scope
+let listEntries = Object.create(null);
 
 /******************************************************************************/
 
-const reBlockStart = /^#block-start-([\w:]+)\n/gm;
-let listEntries = Object.create(null);
+// https://github.com/uBlockOrigin/uBlock-issues/issues/2092
+//   Order of ids matters
 
 const extractBlocks = function(content, ...ids) {
-    reBlockStart.lastIndex = 0;
     const out = [];
-    let match = reBlockStart.exec(content);
-    while ( match !== null ) {
-        const beg = match.index + match[0].length;
-        const id = match[1];
-        if ( ids.includes(id) ) {
-            const end = content.indexOf(`#block-end-${id}`, beg);
-            out.push(content.slice(beg, end));
-            reBlockStart.lastIndex = end;
-        }
-        match = reBlockStart.exec(content);
+    for ( const id of ids ) {
+        const pattern = `#block-start-${id}\n`;
+        let beg = content.indexOf(pattern);
+        if ( beg === -1 ) { continue; }
+        beg += pattern.length;
+        const end = content.indexOf(`#block-end-${id}`, beg);
+        out.push(content.slice(beg, end));
     }
     return out.join('\n');
 };
 
+/******************************************************************************/
+
 // https://github.com/MajkiIT/polish-ads-filter/issues/14768#issuecomment-536006312
 //   Avoid reporting badfilter-ed filters.
 
@@ -66,8 +63,7 @@ const fromNetFilter = function(details) {
             // We need an exact match.
             // https://github.com/gorhill/uBlock/issues/1392
             // https://github.com/gorhill/uBlock/issues/835
-            const notFound = pos !== 0 &&
-                             content.charCodeAt(pos - 1) !== 0x0A;
+            const notFound = pos !== 0 && content.charCodeAt(pos - 1) !== 0x0A;
             pos += compiledFilter.length;
             if (
                 notFound ||
@@ -90,6 +86,8 @@ const fromNetFilter = function(details) {
     self.postMessage({ id: details.id, response });
 };
 
+/******************************************************************************/
+
 // Looking up filter lists from a cosmetic filter is a bit more complicated
 // than with network filters:
 //
@@ -110,7 +108,7 @@ const fromNetFilter = function(details) {
 // FilterContainer.fromCompiledContent() is our reference code to create
 // the various compiled versions.
 
-const fromCosmeticFilter = function(details) {
+const fromExtendedFilter = function(details) {
     const match = /^#@?#\^?/.exec(details.rawFilter);
     const prefix = match[0];
     const exception = prefix.charAt(1) === '@';
@@ -161,8 +159,8 @@ const fromCosmeticFilter = function(details) {
         if ( entry === undefined ) { continue; }
         const content = extractBlocks(
             entry.content,
-            'COSMETIC_FILTERS:GENERIC',
             'COSMETIC_FILTERS:SPECIFIC',
+            'COSMETIC_FILTERS:GENERIC',
             'SCRIPTLET_FILTERS',
             'HTML_FILTERS',
             'HTTPHEADER_FILTERS'
@@ -270,7 +268,9 @@ const fromCosmeticFilter = function(details) {
     self.postMessage({ id: details.id, response });
 };
 
-self.onmessage = function(e) { // jshint ignore:line
+/******************************************************************************/
+
+self.onmessage = function(e) {
     const msg = e.data;
 
     switch ( msg.what ) {
@@ -286,15 +286,10 @@ self.onmessage = function(e) { // jshint ignore:line
         fromNetFilter(msg);
         break;
 
-    case 'fromCosmeticFilter':
-        fromCosmeticFilter(msg);
+    case 'fromExtendedFilter':
+        fromExtendedFilter(msg);
         break;
     }
 };
 
 /******************************************************************************/
-
-// <<<<< end of local scope
-}
-
-/******************************************************************************/
diff --git a/src/js/reverselookup.js b/src/js/reverselookup.js
index ed6b8288c..5ffe41b63 100644
--- a/src/js/reverselookup.js
+++ b/src/js/reverselookup.js
@@ -155,7 +155,7 @@ const fromNetFilter = async function(rawFilter) {
     });
 };
 
-const fromCosmeticFilter = async function(details) {
+const fromExtendedFilter = async function(details) {
     if (
         typeof details.rawFilter !== 'string' ||
         details.rawFilter === ''
@@ -169,7 +169,7 @@ const fromCosmeticFilter = async function(details) {
     const hostname = hostnameFromURI(details.url);
 
     worker.postMessage({
-        what: 'fromCosmeticFilter',
+        what: 'fromExtendedFilter',
         id: id,
         domain: domainFromHostname(hostname),
         hostname: hostname,
@@ -203,7 +203,7 @@ const resetLists = function() {
 
 const staticFilteringReverseLookup = {
     fromNetFilter,
-    fromCosmeticFilter,
+    fromExtendedFilter,
     resetLists,
     shutdown: stopWorker
 };