Redirect /download/releases/X.Y.Z to /downloads/release/python-XYZ

Also, migrate content in the former into the latter.

Fixes #956

downloads/migrations/0005_move_release_page_content.py

@@ -0,0 +1,53 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.4 on 2017-09-23 10:13
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+MARKER = '.. Migrated from Release.release_page field.\n\n'
+
+
+def migrate_old_content(apps, schema_editor):
+    Release = apps.get_model('downloads', 'Release')
+    db_alias = schema_editor.connection.alias
+    releases = Release.objects.using(db_alias).filter(
+        release_page__isnull=False,
+    )
+    for release in releases:
+        content = '\n'.join(release.release_page.content.raw.splitlines()[3:])
+        release.content = MARKER + content
+        release.release_page = None
+        release.save()
+
+
+def delete_migrated_content(apps, schema_editor):
+    Release = apps.get_model('downloads', 'Release')
+    Page = apps.get_model('pages', 'Page')
+    db_alias = schema_editor.connection.alias
+    releases = Release.objects.using(db_alias).filter(
+        release_page__isnull=True,
+        content__startswith=MARKER,
+    )
+    for release in releases:
+        try:
+            name = release.name
+            if 'Release' not in name:
+                name = release.name + ' Release'
+            page = Page.objects.get(title=name)
+        except (Page.DoesNotExist, Page.MultipleObjectsReturned):
+            continue
+        else:
+            release.release_page = page
+            release.content = ''
+            release.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('downloads', '0004_auto_20170821_2000'),
+    ]
+
+    operations = [
+        migrations.RunPython(migrate_old_content, delete_migrated_content),
+    ]

downloads/tests/base.py

@@ -29,7 +29,7 @@ class BaseDownloadTests(DownloadMixin):
 
     def setUp(self):
         self.release_275_page = Page.objects.create(
-            title='Python 2.7.5',
+            title='Python 2.7.5 Release',
             path='download/releases/2.7.5',
             content='whatever',
             is_published=True,

downloads/tests/test_views.py

@@ -28,7 +28,7 @@
 }
 
 
-class DownloadViewsTests(BaseDownloadTests):
+class DownloadViewsTests(BaseDownloadTests, TestCase):
     def test_download_full_os_list(self):
         url = reverse('download:download_full_os_list')
         response = self.client.get(url)
@@ -64,6 +64,19 @@ def test_latest_redirects(self):
         response = self.client.get(url)
         self.assertRedirects(response, latest_python3.get_absolute_url())
 
+    def test_redirect_page_object_to_release_detail_page(self):
+        self.release_275.release_page = None
+        self.release_275.save()
+        response = self.client.get(self.release_275_page.get_absolute_url())
+        self.assertRedirects(
+            response,
+            reverse(
+                'download:download_release_detail',
+                kwargs={'release_slug': self.release_275.slug},
+            ),
+            status_code=301,
+        )
+
 
 class RegressionTests(DownloadMixin, TestCase):
     """These tests are for bugs found by Sentry."""

pages/views.py

@@ -1,5 +1,10 @@
+import re
+
+from django.http import HttpResponsePermanentRedirect
+from django.urls import reverse
 from django.views.generic import DetailView
 
+from downloads.models import Release
 from .models import Page
 
 
@@ -37,3 +42,24 @@ def get_extra_context(self, *args, **kwargs):
         context = self.super().get_extra_context(*args, **kwargs)
         context['in_pages_app'] = True
         return context
+
+    def get(self, request, *args, **kwargs):
+        # Redirect '/download/releases/X.Y.Z' to
+        # '/downloads/release/python-XYZ/' if the latter URL doesn't have
+        # 'release_page' (which points to the former URL) field set.
+        # See #956 for details.
+        matched = re.match(r'/download/releases/([\d.]+)/$', self.request.path)
+        if matched is not None:
+            release_slug = 'python-{}'.format(matched.group(1).replace('.', ''))
+            try:
+                Release.objects.get(slug=release_slug, release_page__isnull=True)
+            except Release.DoesNotExist:
+                pass
+            else:
+                return HttpResponsePermanentRedirect(
+                    reverse(
+                        'download:download_release_detail',
+                        kwargs={'release_slug': release_slug},
+                    )
+                )
+        return super().get(request, *args, **kwargs)