Fixed #23387 -- Kept "Save as new" button after validation errors in admin.

When "Save as new" is chosen and errors occur, only show the "Save as new"
button and not the other save buttons.

Thanks to Tino de Bruijn for doing the real work on this fix.

django/contrib/admin/options.py

@@ -1342,9 +1342,8 @@ class ModelAdmin(BaseModelAdmin):
                     'name': force_text(opts.verbose_name), 'key': escape(object_id)})
 
             if request.method == 'POST' and "_saveasnew" in request.POST:
-                return self.add_view(request, form_url=reverse('admin:%s_%s_add' % (
-                    opts.app_label, opts.model_name),
-                    current_app=self.admin_site.name))
+                object_id = None
+                obj = None
 
         ModelForm = self.get_form(request, obj)
         if request.method == 'POST':
@@ -1366,6 +1365,8 @@ class ModelAdmin(BaseModelAdmin):
                 else:
                     self.log_change(request, new_object, change_message)
                     return self.response_change(request, new_object)
+            else:
+                form_validated = False
         else:
             if add:
                 initial = self.get_changeform_initial_data(request)
@@ -1401,6 +1402,12 @@ class ModelAdmin(BaseModelAdmin):
             preserved_filters=self.get_preserved_filters(request),
         )
 
+        # Hide the "Save" and "Save and continue" buttons if "Save as New" was
+        # previously chosen to prevent the interface from getting confusing.
+        if request.method == 'POST' and not form_validated and "_saveasnew" in request.POST:
+            context['show_save'] = False
+            context['show_save_and_continue'] = False
+
         context.update(extra_context or {})
 
         return self.render_change_form(request, context, add=add, change=not add, obj=obj, form_url=form_url)

django/contrib/admin/templatetags/admin_modify.py

@@ -30,6 +30,8 @@ def submit_row(context):
     change = context['change']
     is_popup = context['is_popup']
     save_as = context['save_as']
+    show_save = context.get('show_save', True)
+    show_save_and_continue = context.get('show_save_and_continue', True)
     ctx = {
         'opts': opts,
         'show_delete_link': (
@@ -41,9 +43,9 @@ def submit_row(context):
             context['has_add_permission'] and not is_popup and
             (not save_as or context['add'])
         ),
-        'show_save_and_continue': not is_popup and context['has_change_permission'],
+        'show_save_and_continue': not is_popup and context['has_change_permission'] and show_save_and_continue,
         'is_popup': is_popup,
-        'show_save': True,
+        'show_save': show_save,
         'preserved_filters': context.get('preserved_filters'),
     }
     if context.get('original') is not None:

tests/admin_views/admin.py

@@ -288,6 +288,7 @@ class ChildInline(admin.StackedInline):
 class ParentAdmin(admin.ModelAdmin):
     model = Parent
     inlines = [ChildInline]
+    save_as = True
 
     list_editable = ('name',)
 

tests/admin_views/models.py

@@ -10,6 +10,7 @@ from django.contrib.contenttypes.fields import (
     GenericForeignKey, GenericRelation,
 )
 from django.contrib.contenttypes.models import ContentType
+from django.core.exceptions import ValidationError
 from django.core.files.storage import FileSystemStorage
 from django.db import models
 from django.utils.encoding import python_2_unicode_compatible
@@ -311,11 +312,19 @@ class Vodcast(Media):
 class Parent(models.Model):
     name = models.CharField(max_length=128)
 
+    def clean(self):
+        if self.name == '_invalid':
+            raise ValidationError('invalid')
+
 
 class Child(models.Model):
     parent = models.ForeignKey(Parent, editable=False)
     name = models.CharField(max_length=30, blank=True)
 
+    def clean(self):
+        if self.name == '_invalid':
+            raise ValidationError('invalid')
+
 
 @python_2_unicode_compatible
 class EmptyModel(models.Model):

tests/admin_views/tests.py

@@ -1151,18 +1151,59 @@ class SaveAsTests(TestCase):
         self.assertEqual(len(Person.objects.filter(name='John M')), 1)
         self.assertEqual(len(Person.objects.filter(id=self.per1.pk)), 1)
 
-    def test_save_as_display(self):
+    def test_save_as_new_with_validation_errors(self):
         """
-        Ensure that 'save as' is displayed when activated and after submitting
-        invalid data aside save_as_new will not show us a form to overwrite the
-        initial model.
+        Ensure that when you click "Save as new" and have a validation error,
+        you only see the "Save as new" button and not the other save buttons,
+        and that only the "Save as" button is visible.
         """
-        change_url = reverse('admin:admin_views_person_change', args=(self.per1.pk,))
-        response = self.client.get(change_url)
-        self.assertTrue(response.context['save_as'])
-        post_data = {'_saveasnew': '', 'name': 'John M', 'gender': 3, 'alive': 'checked'}
-        response = self.client.post(change_url, post_data)
-        self.assertEqual(response.context['form_url'], reverse('admin:admin_views_person_add'))
+        response = self.client.post(reverse('admin:admin_views_person_change', args=(self.per1.pk,)), {
+            '_saveasnew': '',
+            'gender': 'invalid',
+            '_addanother': 'fail',
+        })
+        self.assertContains(response, 'Please correct the errors below.')
+        self.assertFalse(response.context['show_save_and_add_another'])
+        self.assertFalse(response.context['show_save_and_continue'])
+        self.assertTrue(response.context['show_save_as_new'])
+
+    def test_save_as_new_with_validation_errors_with_inlines(self):
+        parent = Parent.objects.create(name='Father')
+        child = Child.objects.create(parent=parent, name='Child')
+        response = self.client.post(reverse('admin:admin_views_parent_change', args=(parent.pk,)), {
+            '_saveasnew': 'Save as new',
+            'child_set-0-parent': parent.pk,
+            'child_set-0-id': child.pk,
+            'child_set-0-name': 'Child',
+            'child_set-INITIAL_FORMS': 1,
+            'child_set-MAX_NUM_FORMS': 1000,
+            'child_set-MIN_NUM_FORMS': 0,
+            'child_set-TOTAL_FORMS': 4,
+            'name': '_invalid',
+        })
+        self.assertContains(response, 'Please correct the error below.')
+        self.assertFalse(response.context['show_save_and_add_another'])
+        self.assertFalse(response.context['show_save_and_continue'])
+        self.assertTrue(response.context['show_save_as_new'])
+
+    def test_save_as_new_with_inlines_with_validation_errors(self):
+        parent = Parent.objects.create(name='Father')
+        child = Child.objects.create(parent=parent, name='Child')
+        response = self.client.post(reverse('admin:admin_views_parent_change', args=(parent.pk,)), {
+            '_saveasnew': 'Save as new',
+            'child_set-0-parent': parent.pk,
+            'child_set-0-id': child.pk,
+            'child_set-0-name': '_invalid',
+            'child_set-INITIAL_FORMS': 1,
+            'child_set-MAX_NUM_FORMS': 1000,
+            'child_set-MIN_NUM_FORMS': 0,
+            'child_set-TOTAL_FORMS': 4,
+            'name': 'Father',
+        })
+        self.assertContains(response, 'Please correct the error below.')
+        self.assertFalse(response.context['show_save_and_add_another'])
+        self.assertFalse(response.context['show_save_and_continue'])
+        self.assertTrue(response.context['show_save_as_new'])
 
 
 @override_settings(ROOT_URLCONF="admin_views.urls")