From f10b1003793a54d5d04c819e94cad02c78e10a82 Mon Sep 17 00:00:00 2001
From: Raymond Hill <rhill@raymondhill.net>
Date: Sun, 21 Apr 2019 07:49:44 -0400
Subject: [PATCH] Fix the handling of pseudoclass-based generic cosmetic
 filters

Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/464

Regression from:
https://github.com/gorhill/uBlock/commit/261ef8c510fd91ead57948d1f7793a7a5e2a25fd?diff=unified#diff-3b15596213ed9ba37fb5b8bb1402a6c2R599

Pseudoclass-based generic cosmetic filters were improperly seen
as invalid following the regression.
---
 src/js/cosmetic-filtering.js   |  9 +++++++-
 src/js/static-ext-filtering.js | 38 +++++++++++++++-------------------
 2 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/src/js/cosmetic-filtering.js b/src/js/cosmetic-filtering.js
index f03fdf680..dc2217dcb 100644
--- a/src/js/cosmetic-filtering.js
+++ b/src/js/cosmetic-filtering.js
@@ -596,7 +596,14 @@ FilterContainer.prototype.compileGenericHideSelector = function(
     // - Bad syntax
     // - Procedural filters (can't be generic): the compiled version of
     //   a procedural selector is NEVER equal to its raw version.
-    if ( compiled === undefined || compiled !== selector ) {
+    // https://github.com/uBlockOrigin/uBlock-issues/issues/464
+    //   Pseudoclass-based selectors can be compiled, but are also valid
+    //   plain selectors.
+    if (
+        compiled === undefined ||
+        compiled !== selector &&
+        µb.staticExtFilteringEngine.compileSelector.pseudoclass !== true
+    ) {
         const who = writer.properties.get('assetKey') || '?';
         µb.logger.writeOne({
             realm: 'message',
diff --git a/src/js/static-ext-filtering.js b/src/js/static-ext-filtering.js
index e8c8a9535..fb5670b4d 100644
--- a/src/js/static-ext-filtering.js
+++ b/src/js/static-ext-filtering.js
@@ -467,7 +467,7 @@
             return µb.cosmeticFilteringEngine.discardedCount +
                    µb.scriptletFilteringEngine.discardedCount +
                    µb.htmlFilteringEngine.discardedCount;
-        }
+        },
     };
 
     //--------------------------------------------------------------------------
@@ -664,6 +664,8 @@
         };
 
         const entryPoint = function(raw) {
+            entryPoint.pseudoclass = false;
+
             const extendedSyntax = reExtendedSyntax.test(raw);
             if ( isValidCSSSelector(raw) && extendedSyntax === false ) {
                 return raw;
@@ -672,18 +674,18 @@
             // We  rarely reach this point -- majority of selectors are plain
             // CSS selectors.
 
-            let matches, operator;
+            let matches;
 
-            // Supported Adguard/ABP advanced selector syntax: will translate into
-            // uBO's syntax before further processing.
+            // Supported Adguard/ABP advanced selector syntax: will translate
+            // into uBO's syntax before further processing.
             // Mind unsupported advanced selector syntax, such as ABP's
             // `-abp-properties`.
-            // Note: extended selector syntax has been deprecated in ABP, in favor
-            // of the procedural one (i.e. `:operator(...)`). See
-            // https://issues.adblockplus.org/ticket/5287
+            // Note: extended selector syntax has been deprecated in ABP, in
+            // favor of the procedural one (i.e. `:operator(...)`).
+            // See https://issues.adblockplus.org/ticket/5287
             if ( extendedSyntax ) {
                 while ( (matches = reExtendedSyntaxParser.exec(raw)) !== null ) {
-                    operator = normalizedExtendedSyntaxOperators.get(matches[1]);
+                    const operator = normalizedExtendedSyntaxOperators.get(matches[1]);
                     if ( operator === undefined ) { return; }
                     raw = raw.slice(0, matches.index) +
                           operator + '(' + matches[3] + ')' +
@@ -692,8 +694,7 @@
                 return entryPoint(raw);
             }
 
-            let selector = raw,
-                pseudoclass, style;
+            let selector = raw, pseudoclass, style;
 
             // `:style` selector?
             if ( (matches = reStyleSelector.exec(selector)) !== null ) {
@@ -709,23 +710,16 @@
             }
 
             if ( style !== undefined || pseudoclass !== undefined ) {
-                if ( isValidCSSSelector(selector) === false ) {
-                    return;
-                }
+                if ( isValidCSSSelector(selector) === false ) { return; }
                 if ( pseudoclass !== undefined ) {
                     selector += pseudoclass;
                 }
                 if ( style !== undefined ) {
                     if ( isValidStyleProperty(style) === false ) { return; }
-                    return JSON.stringify({
-                        raw: raw,
-                        style: [ selector, style ]
-                    });
+                    return JSON.stringify({ raw, style: [ selector, style ] });
                 }
-                return JSON.stringify({
-                    raw: raw,
-                    pseudoclass: true
-                });
+                entryPoint.pseudoclass = true;
+                return JSON.stringify({ raw, pseudoclass: true });
             }
 
             // Procedural selector?
@@ -735,6 +729,8 @@
             }
         };
 
+        entryPoint.pseudoclass = false;
+
         return entryPoint;
     })();