From 2afbd3412988f2c7c5a83e92c3b5b1332419bf24 Mon Sep 17 00:00:00 2001
From: Nicolai Ehrhardt <245527909+predictor2718@users.noreply.github.com>
Date: Wed, 29 Apr 2026 21:15:01 +0200
Subject: [PATCH] Fix #20256 - Restore active preferences tab after page
 refresh via location.hash

Signed-off-by: Nicolai Ehrhardt <245527909+predictor2718@users.noreply.github.com>
---
 js/src/config.js                     | 38 ++++++++++++++++++++++++++++
 test/selenium/ServerSettingsTest.php | 26 +++++++++++++++++++
 2 files changed, 64 insertions(+)

diff --git a/js/src/config.js b/js/src/config.js
index 093993b36e..d6a1f06477 100644
--- a/js/src/config.js
+++ b/js/src/config.js
@@ -44,6 +44,7 @@ AJAX.registerTeardown('config.js', function () {
     $('form.prefs-form').off('change').off('submit');
     $(document).off('click', 'div.click-hide-message');
     $('#prefs_autoload').find('a').off('click');
+    $('form.config-form').off('shown.bs.tab');
 });
 
 AJAX.registerOnload('config.js', function () {
@@ -52,6 +53,43 @@ AJAX.registerOnload('config.js', function () {
     $topmenuUpt.find('a:not(.active)').attr('rel', 'newpage');
 });
 
+// ------------------------------------------------------------------
+// Tabbed forms - tab state persistence via location.hash
+//
+
+function setupConfigTabsPersistence () {
+    var $form = $('form.config-form');
+    if (!$form.length) {
+        return;
+    }
+
+    // Activate the tab indicated by the URL hash on page load
+    var hash = window.location.hash;
+    if (hash && /^#[a-zA-Z0-9_]+$/.test(hash)) {
+        var $tabLink = $form.find('a[data-bs-toggle="tab"][href="' + hash + '"]');
+        if ($tabLink.length) {
+            bootstrap.Tab.getOrCreateInstance($tabLink[0]).show();
+        }
+    }
+
+    // Keep the URL hash and the tab_hash hidden input in sync when the user switches tabs
+    $form.on('shown.bs.tab', '[data-bs-toggle="tab"]', function () {
+        var href = $(this).attr('href');
+        if (href) {
+            window.location.hash = href;
+            $form.find('input[name="tab_hash"]').val(href.replace(/^#/, ''));
+        }
+    });
+}
+
+AJAX.registerOnload('config.js', function () {
+    setupConfigTabsPersistence();
+});
+
+//
+// END: Tabbed forms
+// ------------------------------------------------------------------
+
 // default values for fields
 var defaultValues = {};
 
diff --git a/test/selenium/ServerSettingsTest.php b/test/selenium/ServerSettingsTest.php
index 2111b6eaa7..edbc3b489c 100644
--- a/test/selenium/ServerSettingsTest.php
+++ b/test/selenium/ServerSettingsTest.php
@@ -101,6 +101,32 @@ class ServerSettingsTest extends TestBase
         self::assertTrue($this->byId('Sql_queries')->isDisplayed());
     }
 
+    /**
+     * Tests that the active preferences tab is restored after a page refresh
+     *
+     * @group large
+     */
+    public function testActiveTabRestoredAfterRefresh(): void
+    {
+        $this->byPartialLinkText('Main panel')->click();
+        $this->waitAjax();
+
+        $this->waitForElement('className', 'nav-tabs');
+
+        // Switch to a non-default tab
+        $this->byCssSelector("a[href='#Tabs']")->click();
+        self::assertTrue($this->byId('Tabs')->isDisplayed());
+        self::assertFalse($this->byId('Startup')->isDisplayed());
+
+        // Reload the page – the hash is preserved in the URL
+        $this->reloadPage();
+        $this->waitAjax();
+
+        // The previously active tab must still be shown
+        self::assertTrue($this->byId('Tabs')->isDisplayed());
+        self::assertFalse($this->byId('Startup')->isDisplayed());
+    }
+
     /**
      * Tests if hiding the logo works or not
      *