this allows to use Adguard filter lists (unsupported filters are discarded)

src/js/cosmetic-filtering.js

@@ -244,7 +244,6 @@ var FilterParser = function() {
     this.hostnames = [];
     this.invalid = false;
     this.cosmetic = true;
-    this.reParser = /^([^#]*?)(##|#@#)(.+)$/;
     this.reScriptContains = /^script:contains\(.+?\)$/;
 };
 
@@ -265,14 +264,59 @@ FilterParser.prototype.parse = function(raw) {
     // important!
     this.reset();
 
-    var matches = this.reParser.exec(raw);
-    if ( matches === null || matches.length !== 4 ) {
+    // Find the bounds of the anchor.
+    var lpos = raw.indexOf('#');
+    if ( lpos === -1 ) {
+        this.cosmetic = false;
+        return this;
+    }
+    var rpos = raw.indexOf('#', lpos + 1);
+    if ( rpos === -1 ) {
+        this.cosmetic = false;
+        return this;
+    }
+
+    // Coarse-check that the anchor is valid.
+    // `##`: l = 1
+    // `#@#`, `#$#`, `#%#`: l = 2
+    // `#@$#`, `#@%#`: l = 3
+    if ( (rpos - lpos) > 3 ) {
+        this.cosmetic = false;
+        return this;
+    }
+
+    // Find out type of cosmetic filter.
+    // Exception filter?
+    if ( raw.charCodeAt(lpos + 1) === 0x40 /* '@' */ ) {
+        this.unhide = 1;
+    }
+
+    // https://github.com/gorhill/uBlock/issues/952
+    // Find out whether we are dealing with an Adguard-specific cosmetic
+    // filter, and if so, discard the filter.
+    var cCode = raw.charCodeAt(rpos - 1);
+    if ( cCode !== 0x23 /* '#' */ && cCode !== 0x40 /* '@' */ ) {
+        // We have an Adguard cosmetic filter if and only if the character is
+        // `$` or `%`, otherwise it's not a cosmetic filter.
+        if ( cCode === 0x24 /* '$' */ || cCode === 0x25 /* '%' */ ) {
+            this.invalid = true;
+        } else {
+            this.cosmetic = false;
+        }
+        return this;
+    }
+
+    // Extract the hostname(s).
+    if ( lpos !== 0 ) {
+        this.prefix = raw.slice(0, lpos);
+    }
+
+    // Extract the selector.
+    this.suffix = raw.slice(rpos + 1);
+    if ( this.suffix.length === 0 ) {
         this.cosmetic = false;
         return this;
     }
-    this.prefix = matches[1].trim();
-    this.unhide = matches[2].charAt(1) === '@' ? 1 : 0;
-    this.suffix = matches[3].trim();
 
     // Cosmetic filters with explicit style properties can apply only:
     // - to specific cosmetic filters (those which apply to a specific site)
@@ -659,6 +703,7 @@ FilterContainer.prototype.compile = function(s, out) {
         return false;
     }
     if ( parsed.invalid ) {
+        //console.error("uBlock Origin> discarding invalid cosmetic filter '%s'", s);
         return true;
     }
 
@@ -847,7 +892,7 @@ FilterContainer.prototype.fromCompiledContent = function(text, lineBeg, skip) {
     var line, fields, filter, key, bucket;
 
     while ( lineBeg < textEnd ) {
-        if ( text.charAt(lineBeg) !== 'c' ) {
+        if ( text.charCodeAt(lineBeg) !== 0x63 /* 'c' */ ) {
             return lineBeg;
         }
         lineEnd = text.indexOf('\n', lineBeg);
@@ -961,7 +1006,7 @@ FilterContainer.prototype.skipCompiledContent = function(text, lineBeg) {
     var textEnd = text.length;
 
     while ( lineBeg < textEnd ) {
-        if ( text.charAt(lineBeg) !== 'c' ) {
+        if ( text.charCodeAt(lineBeg) !== 0x63 /* 'c' */ ) {
             return lineBeg;
         }
         lineEnd = text.indexOf('\n', lineBeg);

src/js/static-net-filtering.js

@@ -1557,6 +1557,12 @@ FilterParser.prototype.parse = function(raw) {
     if ( s.charAt(0) !== '/' || s.slice(-1) !== '/' ) {
         pos = s.lastIndexOf('$');
         if ( pos !== -1 ) {
+            // https://github.com/gorhill/uBlock/issues/952
+            // Discard Adguard-specific `$$` filters.
+            if ( s.indexOf('$$') !== -1 ) {
+                this.unsupported = true;
+                return this;
+            }
             this.parseOptions(s.slice(pos + 1));
             s = s.slice(0, pos);
         }
@@ -1917,12 +1923,6 @@ FilterContainer.prototype.compile = function(raw, out) {
         return false;
     }
 
-    // Ignore comments
-    var c = s.charAt(0);
-    if ( c === '[' || c === '!' ) {
-        return false;
-    }
-
     var parsed = this.filterParser.parse(s);
 
     // Ignore element-hiding filters
@@ -2070,7 +2070,7 @@ FilterContainer.prototype.fromCompiledContent = function(text, lineBeg) {
     var line, fields, bucket, entry, factory, filter;
 
     while ( lineBeg < textEnd ) {
-        if ( text.charAt(lineBeg) !== 'n' ) {
+        if ( text.charCodeAt(lineBeg) !== 0x6E /* 'n' */ ) {
             return lineBeg;
         }
         lineEnd = text.indexOf('\n', lineBeg);