WebUI: Fix memory leak

See #22734, there is a memory leak in the MooTools .destroy(), this replaces all uses of that with the browser native .remove().

This also overrides the MooTools Document.id function, which is used by $(id). The original function always allocates an ID to elements it selects, the override doesn't, and is also a little more efficient.

Closes #22734.
PR  #22754.

---------

Co-authored-by: Chocobo1 <Chocobo1@users.noreply.github.com>

src/webui/www/private/index.html

@@ -26,6 +26,7 @@
     <script defer src="scripts/lib/MooTools-Core-1.6.0-compat-compressed.js"></script>
     <script defer src="scripts/lib/MooTools-More-1.6.0-compat-compressed.js"></script>
     <script defer src="scripts/lib/mocha.min.js"></script>
+    <script defer src="scripts/monkeypatch.js?v=${CACHEID}"></script>
     <script defer src="scripts/cache.js?v=${CACHEID}"></script>
     <script defer src="scripts/localpreferences.js?v=${CACHEID}"></script>
     <script defer src="scripts/color-scheme.js?v=${CACHEID}"></script>

src/webui/www/private/scripts/client.js

@@ -499,7 +499,7 @@ window.addEventListener("DOMContentLoaded", (event) => {
         if (!categoryList)
             return;
 
-        [...categoryList.children].forEach((el) => { el.destroy(); });
+        [...categoryList.children].forEach((el) => { el.remove(); });
 
         const categoryItemTemplate = document.getElementById("categoryFilterItem");
 
@@ -620,7 +620,7 @@ window.addEventListener("DOMContentLoaded", (event) => {
         if (tagFilterList === null)
             return;
 
-        [...tagFilterList.children].forEach((el) => { el.destroy(); });
+        [...tagFilterList.children].forEach((el) => { el.remove(); });
 
         const tagItemTemplate = document.getElementById("tagFilterItem");
 
@@ -673,7 +673,7 @@ window.addEventListener("DOMContentLoaded", (event) => {
         if (trackerFilterList === null)
             return;
 
-        [...trackerFilterList.children].forEach((el) => { el.destroy(); });
+        [...trackerFilterList.children].forEach((el) => { el.remove(); });
 
         const trackerItemTemplate = document.getElementById("trackerFilterItem");
 

src/webui/www/private/scripts/contextmenu.js

@@ -478,7 +478,7 @@ window.qBittorrent.ContextMenu ??= (() => {
 
         updateCategoriesSubMenu(categories) {
             const contextCategoryList = document.getElementById("contextCategoryList");
-            [...contextCategoryList.children].forEach((el) => { el.destroy(); });
+            [...contextCategoryList.children].forEach((el) => { el.remove(); });
 
             const createMenuItem = (text, imgURL, clickFn) => {
                 const anchor = document.createElement("a");

src/webui/www/private/scripts/dynamicTable.js

@@ -900,7 +900,7 @@ window.qBittorrent.DynamicTable ??= (() => {
                 const rowPos = rows.length;
 
                 while ((rowPos < trs.length) && (trs.length > 0))
-                    trs.pop().destroy();
+                    trs.pop().remove();
             }
         }
 
@@ -1022,7 +1022,7 @@ window.qBittorrent.DynamicTable ??= (() => {
             }
             else {
                 const tr = this.getTrByRowId(rowId);
-                tr?.destroy();
+                tr?.remove();
             }
         }
 
@@ -1034,7 +1034,7 @@ window.qBittorrent.DynamicTable ??= (() => {
             }
             else {
                 for (const tr of this.getTrs())
-                    tr.destroy();
+                    tr.remove();
             }
         }
 

src/webui/www/private/scripts/monkeypatch.js

@@ -0,0 +1,72 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2025  bolshoytoster <toasterbig@gmail.com>
+ * Copyright (C) 2025  Mike Tzou (Chocobo1)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+"use strict";
+
+window.qBittorrent ??= {};
+window.qBittorrent.MonkeyPatch ??= (() => {
+    const exports = () => {
+        return {
+            patch: patch
+        };
+    };
+
+    const patch = () => {
+        patchMootoolsDocumentId();
+    };
+
+    const patchMootoolsDocumentId = () => {
+        // Override MooTools' `document.id` (used for `$(id)`), which prevents it
+        // from allocating a `uniqueNumber` for elements that don't need it.
+        // MooTools and MochaUI use it internally.
+
+        if (document.id === undefined)
+            return;
+
+        document.id = (el) => {
+            if ((el === null) || (el === undefined))
+                return null;
+
+            switch (typeof el) {
+                case "object":
+                    return el;
+                case "string":
+                    return document.getElementById(el);
+            }
+
+            return null;
+        };
+    };
+
+    return exports();
+})();
+Object.freeze(window.qBittorrent.MonkeyPatch);
+
+// execute now
+window.qBittorrent.MonkeyPatch.patch();

src/webui/www/private/scripts/search.js

@@ -248,7 +248,7 @@ window.qBittorrent.Search ??= (() => {
         if (state && state.running)
             stopSearch(searchId);
 
-        tab.destroy();
+        tab.remove();
 
         fetch("api/v2/search/delete", {
             method: "POST",

src/webui/www/private/views/cookies.html

@@ -104,7 +104,7 @@
         };
 
         const deleteCookie = (element) => {
-            element.closest("tr").destroy();
+            element.closest("tr").remove();
         };
 
         const save = () => {

src/webui/www/private/views/preferences.html

@@ -2132,7 +2132,7 @@ Use ';' to split multiple entries. Can use wildcard '*'.)QBT_TR[CONTEXT=OptionsD
 
         // Advanced Tab
         const updateNetworkInterfaces = (default_iface, default_iface_name) => {
-            [...document.getElementById("networkInterface").children].forEach((el) => { el.destroy(); });
+            [...document.getElementById("networkInterface").children].forEach((el) => { el.remove(); });
 
             fetch("api/v2/app/networkInterfaceList", {
                     method: "GET",
@@ -2161,7 +2161,7 @@ Use ';' to split multiple entries. Can use wildcard '*'.)QBT_TR[CONTEXT=OptionsD
         };
 
         const updateInterfaceAddresses = (iface, default_addr) => {
-            [...document.getElementById("optionalIPAddressToBind").children].forEach((el) => { el.destroy(); });
+            [...document.getElementById("optionalIPAddressToBind").children].forEach((el) => { el.remove(); });
 
             const url = new URL("api/v2/app/networkInterfaceAddressList", window.location);
             url.search = new URLSearchParams({

src/webui/www/private/views/rss.html

@@ -425,7 +425,7 @@
         };
 
         const clearDetails = () => {
-            [...document.getElementById("rssDetailsView").children].forEach((el) => { el.destroy(); });
+            [...document.getElementById("rssDetailsView").children].forEach((el) => { el.remove(); });
         };
 
         const showDetails = (feedUid, articleID) => {

src/webui/www/webui.qrc

@@ -408,6 +408,7 @@
         <file>private/scripts/localpreferences.js</file>
         <file>private/scripts/misc.js</file>
         <file>private/scripts/mocha-init.js</file>
+        <file>private/scripts/monkeypatch.js</file>
         <file>private/scripts/pathAutofill.js</file>
         <file>private/scripts/piecesbar.js</file>
         <file>private/scripts/progressbar.js</file>