Issue 6811 - Parse blank arguments to snippets correctly

lib/snippets.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 76 matching lines @@
  */
 function parseScript(script)
 {
   let tree = [];
 
   let escape = false;
   let withinQuotes = false;
 
   let unicodeEscape = null;
 
+  let quotesClosed = false;
+
   let call = [];
   let argument = "";
 
   for (let character of script.trim() + ";")
   {
+    let afterQuotesClosed = quotesClosed;
+    quotesClosed = false;
+
     if (unicodeEscape != null)
     {
       unicodeEscape += character;
 
       if (unicodeEscape.length == 4)
       {
         let codePoint = parseInt(unicodeEscape, 16);
         if (!isNaN(codePoint))
           argument += String.fromCodePoint(codePoint);
 
         unicodeEscape = null;
       }
     }
     else if (escape)
     {
       escape = false;
 
       if (character == "u")
         unicodeEscape = "";
       else
         argument += singleCharacterEscapes.get(character) || character;
     }
     else if (character == "\\")
     {
       escape = true;
     }
     else if (character == "'")
     {
       withinQuotes = !withinQuotes;
+
+      if (!withinQuotes)
+        quotesClosed = true;
     }
     else if (withinQuotes || character != ";" && !/\s/.test(character))
     {
       argument += character;
     }
     else
     {
-      if (argument)
+      if (argument || afterQuotesClosed)
       {
         call.push(argument);
         argument = "";
       }
 
       if (character == ";" && call.length > 0)
       {
         tree.push(call);
         call = [];
       }
@@ skipping 31 matching lines @@
           let value = imports[name];
           if (typeof value == "function")
             value(...args);
         }
       }
     }
   `;
 }
 
 exports.compileScript = compileScript;