Issue 4538 - When exporting filters, mark $websocket filters as requiring Adblock Plus 2.8

chrome/content/ui/filters-backup.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 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 301 matching lines @@
         list.push(filter.text);
 
         if (filter instanceof ElemHideException && Services.vc.compare(minVersion, "2.1") < 0)
           minVersion = "2.1";
 
         if (filter instanceof RegExpFilter && filter.contentType & (RegExpFilter.typeMap.GENERICHIDE | RegExpFilter.typeMap.GENERICBLOCK) && Services.vc.compare(minVersion, "2.6.12") < 0)
           minVersion = "2.6.12";
 
         if (filter instanceof CSSPropertyFilter && Services.vc.compare(minVersion, "2.7.3") < 0)
           minVersion = "2.7.3";
+
+        if (filter instanceof RegExpFilter &&
+            (filter.contentType & RegExpFilter.typeMap.WEBSOCKET) &&
+            Services.vc.compare(minVersion, "2.8"))
+        {
+          minVersion = "2.8";
+        }
       }
     }
     list.unshift("[Adblock Plus " + minVersion + "]");
 
     // Insert checksum. Have to add an empty line to the end of the list to
     // account for the trailing newline in the file.
     list.push("");
     let checksum = Utils.generateChecksum(list);
     list.pop();
     if (checksum)
       list.splice(1, 0, "! Checksum: " + checksum);
 
     IO.writeToFile(file, list, function(e)
     {
       if (e)
       {
         Cu.reportError(e);
         Utils.alert(window, E("backupButton").getAttribute("_backupError"), E("backupButton").getAttribute("_backupDialogTitle"));
       }
     });
   }
 };
 
 window.addEventListener("load", function()
 {
   Backup.init();
 }, false);