From 9c6e07a467b9a5eb5cea0140d820e60971d1bfb9 Mon Sep 17 00:00:00 2001
From: catborise <catborise@gmail.com>
Date: Sat, 24 Oct 2026 11:19:02 +0300
Subject: [PATCH] fix(instances): a refused XML definition comes back in its
 editor

On the machine step, "Or define it from XML" lost the definition when it
was refused: a taken name re-rendered the page with an empty, collapsed
editor; malformed XML went on to libvirt, and libvirt's refusal sent the
browser back to an empty page with the reason at the top.

All three refusals now render the page with the section open, the
submitted XML in the editor (and in the field it posts, so it can be sent
again unchanged), and the reason above the editor, which takes the focus.

Fixes #174

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
---
 instances/templates/create_instance_w1.html |  9 +++---
 instances/tests/test_create_form_input.py   | 32 +++++++++++++++++++++
 instances/views.py                          | 20 +++++++------
 3 files changed, 48 insertions(+), 13 deletions(-)

diff --git a/instances/templates/create_instance_w1.html b/instances/templates/create_instance_w1.html
index a532569a..6e33af42 100644
--- a/instances/templates/create_instance_w1.html
+++ b/instances/templates/create_instance_w1.html
@@ -48,14 +48,15 @@
             <div class="card-body">
                 <h2 class="h5 card-title mb-0" id="xml-heading">
                     <button class="btn p-0 border-0 text-body fw-medium w-100 text-start focus-ring disclosure" type="button" data-bs-toggle="collapse" data-bs-target="#from-xml"
-                            aria-expanded="false" aria-controls="from-xml">
+                            aria-expanded="{% if xml_error %}true{% else %}false{% endif %}" aria-controls="from-xml">
                         {% bs_icon 'chevron-down' %} {% trans "Or define it from XML" %}
                     </button>
                 </h2>
-                <div class="collapse" id="from-xml">
+                <div class="collapse{% if xml_error %} show{% endif %}" id="from-xml">
                     <form method="post" class="pt-3" aria-label="{% trans "Create instance from XML" %}">{% csrf_token %}
-                        <input type="hidden" name="dom_xml">
-                        <div class="xmlheight mb-3"><textarea id="editor" aria-label="{% trans "Domain XML" %}"></textarea></div>
+                        {% if xml_error %}<div class="alert alert-danger form-errors" role="alert">{{ xml_error }}</div>{% endif %}
+                        <input type="hidden" name="dom_xml" value="{{ xml }}">
+                        <div class="xmlheight mb-3"><textarea id="editor" aria-label="{% trans "Domain XML" %}">{{ xml }}</textarea></div>
                         <div class="d-flex justify-content-end">
                             <button type="submit" class="btn btn-primary" name="create_xml" onclick="showPleaseWaitDialog()">
                                 {% trans "Create VM" %}
diff --git a/instances/tests/test_create_form_input.py b/instances/tests/test_create_form_input.py
index adef977d..678521db 100644
--- a/instances/tests/test_create_form_input.py
+++ b/instances/tests/test_create_form_input.py
@@ -5,6 +5,9 @@ import json
 import uuid
 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
 from instances.models import Flavor
@@ -262,3 +265,32 @@ class SubmittedListsTests(TestCase):
     def test_only_a_refused_form_sends_lists(self):
         _, response = render_create_page(self)
         self.assertIsNone(self.lists(response))
+
+
+class XmlRefusalTests(TestCase):
+    """A refused XML definition comes back in its open editor, its reason
+    beside it."""
+
+    def post(self, xml):
+        conn = libvirt.open("test:///default")
+        self.addCleanup(conn.close)
+        compute, _ = Compute.objects.get_or_create(name="testdrv", hostname="localhost", login="", password="", type=4)
+        self.client.force_login(get_user_model().objects.create_superuser("xml", "xml@example.com", "pw"))
+        with patch("vrtManager.connection.connection_manager.get_connection", return_value=conn):
+            response = self.client.post(reverse("instances:create_instance_select_type", args=[compute.id]),
+                                        {"create_xml": "", "dom_xml": xml})
+        self.assertEqual(response.status_code, 200)
+        page = html.fromstring(response.content)
+        self.assertIn("show", page.get_element_by_id("from-xml").classes)
+        self.assertEqual(page.xpath("//*[@id='editor']/text()"), [xml])
+        self.assertEqual(page.xpath("//input[@name='dom_xml']/@value"), [xml])
+        return page.xpath("//*[@id='from-xml']//*[contains(@class, 'form-errors')]")[0].text_content()
+
+    def test_a_taken_name(self):
+        self.assertIn("already exists", self.post("<domain type='test'><name>test</name></domain>"))
+
+    def test_malformed_xml(self):
+        self.assertIn("not well-formed", self.post("<domain type='test'><name>new</name>"))
+
+    def test_a_definition_libvirt_refuses(self):
+        self.assertIn("libvirt", self.post("<domain type='nope'><name>new</name><memory>1024</memory></domain>"))
diff --git a/instances/views.py b/instances/views.py
index 7109f8ea..3ba2816f 100755
--- a/instances/views.py
+++ b/instances/views.py
@@ -1975,22 +1975,24 @@ def create_instance_select_type(request, compute_id):
     default_machine = app_settings.INSTANCE_MACHINE_DEFAULT_TYPE
     default_arch = app_settings.INSTANCE_ARCH_DEFAULT_TYPE
 
-    if request.method == "POST":
-        if "create_xml" in request.POST:
-            xml = request.POST.get("dom_xml", "")
-            try:
-                name = util.get_xml_path(xml, "/domain/name")
-            except util.etree.Error:
-                name = None
+    # a refused definition comes back in the editor, its reason beside it
+    xml_error = None
+    if request.method == "POST" and "create_xml" in request.POST:
+        xml = request.POST.get("dom_xml", "")
+        try:
+            name = util.get_xml_path(xml, "/domain/name")
             if name in instances:
-                error_msg = _("A virtual machine with this name already exists")
-                messages.error(request, error_msg)
+                xml_error = _("A virtual machine with this name already exists")
             else:
                 with libvirt_compute_lock(compute):
                     conn._defineXML(xml)
                     utils.refr(compute)
                     instance = compute.instance_set.get(name=name)
                 return redirect(reverse("instances:instance", args=[instance.id]))
+        except util.etree.Error as err:
+            xml_error = _("The XML is not well-formed: %(error)s") % {"error": err}
+        except libvirtError as err:
+            xml_error = _("libvirt Error - %(exception)s") % {"exception": error_text(request, err)}
 
     return render(request, "create_instance_w1.html", locals())