Change link avoidance mechanism in filters

lib/channel/chat.js

@@ -8,6 +8,9 @@ var url = require("url");
 
 const SHADOW_TAG = "[shadow]";
 const LINK = /(\w+:\/\/(?:[^:\/\[\]\s]+|\[[0-9a-f:]+\])(?::\d+)?(?:\/[^\/\s]*)*)/ig;
+const LINK_PLACEHOLDER = '\ueeee';
+const LINK_PLACEHOLDER_RE = /\ueeee/g;
+
 const TYPE_CHAT = {
     msg: "string",
     meta: "object,optional"
@@ -304,34 +307,31 @@ ChatModule.prototype.formatMessage = function (username, data) {
     return obj;
 };
 
-const link = /(\w+:\/\/(?:[^:\/\[\]\s]+|\[[0-9a-f:]+\])(?::\d+)?(?:\/[^\/\s]*)*)/ig;
 ChatModule.prototype.filterMessage = function (msg) {
     var filters = this.channel.modules.filters.filters;
     var chan = this.channel;
-    var parts = msg.split(link);
     var convertLinks = this.channel.modules.options.get("enable_link_regex");
+    var links = msg.match(LINK);
+    var intermediate = msg.replace(LINK, LINK_PLACEHOLDER);
 
-    for (var j = 0; j < parts.length; j++) {
+    var result = filters.filter(intermediate, false);
-        /* substring is a URL */
+    result = result.replace(LINK_PLACEHOLDER_RE, function () {
-        if (convertLinks && parts[j].match(link)) {
+        var link = links.shift();
-            var original = parts[j];
+        if (!link) {
-            parts[j] = filters.filter(parts[j], true);
+            return '';
-
-            /* no filters changed the URL, apply link filter */
-            if (parts[j] === original) {
-                parts[j] = url.format(url.parse(parts[j]));
-                parts[j] = parts[j].replace(link, "<a href=\"$1\" target=\"_blank\">$1</a>");
         }
 
+        var filtered = filters.filter(link, true);
+        if (filtered !== link) {
+            return filtered;
+        } else if (convertLinks) {
+            return "<a href=\"" + link + "\" target=\"_blank\">" + link + "</a>";
         } else {
-            /* substring is not a URL */
+            return link;
-            parts[j] = filters.filter(parts[j], false);
-        }
         }
+    });
 
-    msg = parts.join("");
+    return XSS.sanitizeHTML(result);
-    /* Anti-XSS */
-    return XSS.sanitizeHTML(msg);
 };
 
 ChatModule.prototype.sendModMessage = function (msg, minrank) {