From d14a31186258842029c4bef19dc40c8fcb58919a Mon Sep 17 00:00:00 2001
From: catborise <catborise@gmail.com>
Date: Mon, 19 Oct 2026 22:09:04 +0300
Subject: [PATCH] fix(instances): the disk bus list follows the device type on
 the create page

Changing a disk's device type in the custom create form asked for its
buses at /archs/undefined/machines/undefined/...: the script read the
architecture and machine from a select[name=arch] and #machine-control
the page does not have. The request failed (500) and the bus list kept
the disk's buses, so a CD-ROM could be put on virtio. The script takes
both from the page's own URL.
---
 instances/templates/create_instance_w2.html |  5 +--
 instances/tests/test_create_page_js.py      | 39 +++++++++++++++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)
 create mode 100644 instances/tests/test_create_page_js.py

diff --git a/instances/templates/create_instance_w2.html b/instances/templates/create_instance_w2.html
index b5f2ee09..5af065be 100644
--- a/instances/templates/create_instance_w2.html
+++ b/instances/templates/create_instance_w2.html
@@ -921,8 +921,9 @@
     }
 
     function get_disk_bus_choices(compute_id, dev_idx, disk_type){
-        let arch = $('select[name="arch"]').val();
-        let machine = $("select[id='machine-control']").val();
+        // the page's own architecture and machine type, from its URL
+        let arch = "{{ arch|escapejs }}";
+        let machine = "{{ machine|escapejs }}";
         get_diskBus_url = "/computes/" + compute_id + "/archs/" + arch + "/machines/" + machine + "/disks/" + disk_type + "/buses";
         $.getJSON(get_diskBus_url, function (data) {
             $("#bus" + dev_idx).find('option').remove();
diff --git a/instances/tests/test_create_page_js.py b/instances/tests/test_create_page_js.py
new file mode 100644
index 00000000..1f3d02f0
--- /dev/null
+++ b/instances/tests/test_create_page_js.py
@@ -0,0 +1,39 @@
+"""Scripts of the VM create page, rendered on libvirt's test driver and run
+in Node against stand-ins."""
+
+import re
+import shutil
+import subprocess
+import unittest
+from unittest.mock import patch
+
+import libvirt
+from computes.models import Compute
+from django.contrib.auth import get_user_model
+from django.test import TestCase
+from django.urls import reverse
+
+
+class CreatePageScriptTests(TestCase):
+    def page(self):
+        conn = libvirt.open("test:///default")
+        self.addCleanup(conn.close)
+        compute = Compute.objects.create(name="testdrv", hostname="localhost", login="", password="", type=4)
+        self.client.force_login(get_user_model().objects.create_superuser("js", "js@example.com", "pw"))
+        with patch("vrtManager.connection.connection_manager.get_connection", return_value=conn), \
+             patch("vrtManager.connection.wvmConnect.get_machine_types", return_value=["pc"]), \
+             patch("vrtManager.connection.wvmConnect.get_nwfilters", return_value=[]):
+            response = self.client.get(reverse("instances:create_instance", args=[compute.id, "i686", "pc"]))
+        self.assertEqual(response.status_code, 200)
+        return compute, response.content.decode()
+
+    @unittest.skipUnless(shutil.which("node"), "node is not installed")
+    def test_the_disk_bus_list_is_asked_for_the_page_architecture_and_machine(self):
+        compute, page = self.page()
+        function = re.search(r"function get_disk_bus_choices\(.*?\n    }\n", page, re.S).group(0)
+        script = "let asked; const $ = Object.assign(() => ({find: () => ({remove() {}}), append() {}, val() {}}), " \
+                 "{getJSON: url => { asked = url; }, each() {}});\n" + function + \
+                 f"get_disk_bus_choices({compute.id}, 0, 'cdrom'); console.log(asked);"
+        result = subprocess.run(["node", "-e", script], capture_output=True, text=True, timeout=30)
+        self.assertEqual(result.returncode, 0, result.stderr)
+        self.assertEqual(result.stdout.strip(), reverse("buses", args=[compute.id, "i686", "pc", "cdrom"]))