new cosmetic filter to foil specific inline script tags

src/js/contentscript-start.js

@@ -74,6 +74,7 @@ var localMessager = vAPI.messaging.channel('contentscript-start.js');
 var cosmeticFilters = function(details) {
     var donthideCosmeticFilters = {};
     var hideCosmeticFilters = {};
+    var scriptTagFilters = [];
     var donthide = details.cosmeticDonthide;
     var hide = details.cosmeticHide;
     var i;
@@ -91,9 +92,14 @@ var cosmeticFilters = function(details) {
             selector = hide[i];
             if ( donthideCosmeticFilters[selector] ) {
                 hide.splice(i, 1);
-            } else {
-                hideCosmeticFilters[selector] = true;
+                continue;
             }
+            if ( selector.lastIndexOf('script//:', 0) === 0 ) {
+                scriptTagFilters.push(selector.slice(9));
+                hide.splice(i, 1);
+                continue;
+            }
+            hideCosmeticFilters[selector] = true;
         }
     }
     if ( hide.length !== 0 ) {
@@ -111,6 +117,11 @@ var cosmeticFilters = function(details) {
     }
     vAPI.donthideCosmeticFilters = donthideCosmeticFilters;
     vAPI.hideCosmeticFilters = hideCosmeticFilters;
+
+    if ( scriptTagFilters.length !== 0 ) {
+        vAPI.reScriptTagFilters = new RegExp(scriptTagFilters.join('|'));
+        document.addEventListener('beforescriptexecute', onBeforeScriptExecuteHandler);
+    }
 };
 
 var netFilters = function(details) {
@@ -128,6 +139,13 @@ var netFilters = function(details) {
     //console.debug('document.querySelectorAll("%s") = %o', text, document.querySelectorAll(text));
 };
 
+var onBeforeScriptExecuteHandler = function(ev) {
+    if ( vAPI.reScriptTagFilters.test(ev.target.textContent) ) {
+        ev.preventDefault();
+        ev.stopPropagation();
+    }
+};
+
 var filteringHandler = function(details) {
     var styleTagCount = vAPI.styles.length;
 

src/js/cosmetic-filtering.js

@@ -283,6 +283,20 @@ FilterParser.prototype.parse = function(s) {
         this.suffix = this.suffix.slice(1);
     }
 
+    // Script tag filters: pre-process them so that can be used with minimal
+    // overhead in the content script.
+    if (
+        this.suffix.lastIndexOf('script:contains(/', 0) === 0 &&
+        this.suffix.slice(-2) === '/)'
+    ) {
+        // Currently supported only as non-generic selector.
+        if ( this.prefix.length === 0 ) {
+            this.invalid = true;
+            return this;
+        }
+        this.suffix = 'script//:' + this.suffix.slice(17, -2).replace(/\\/g, '\\');
+    }
+
     this.unhide = matches[2].charAt(1) === '@' ? 1 : 0;
     if ( this.prefix !== '' ) {
         this.hostnames = this.prefix.split(/\s*,\s*/);
@@ -576,11 +590,14 @@ FilterContainer.prototype.isValidSelector = (function() {
         try {
             // https://github.com/gorhill/uBlock/issues/693
             div.matches(s + ',\n#foo');
+            return true;
         } catch (e) {
-            console.error('uBlock> invalid cosmetic filter:', s);
-            return false;
         }
-        return true;
+        if ( s.lastIndexOf('script//:', 0) === 0 ) {
+            return true;
+        }
+        console.error('uBlock> invalid cosmetic filter:', s);
+        return false;
     };
 })();