[PATCH] views: Raise 404 if downloading non-existent dependencies

[Stephen Finucane]

If a patch was processed by Patchwork before series support was added,
it will not have a series associated with it. As a result, it is not
possible to extract the dependencies for that patch from the series and
a 404 should be raised. This was not previously handled correctly.

Signed-off-by: Stephen Finucane <stephen at that.guru>
Reported-by: John McNamara <john.mcnamara at intel.com>
Fixes: e2dfd490 ("views: Add 'series' parameter to '/mbox' endpoint")
Closes: #189
---
NOTE: This needs to be backported to stable/2.0 once merged to master as
it's an issue there too.
---
 patchwork/tests/test_mboxviews.py             | 24 +++++++++++++++++++
 patchwork/views/patch.py                      |  5 ++++
 .../notes/issue-189-fe4024f33e1b5203.yaml     |  7 ++++++
 3 files changed, 36 insertions(+)
 create mode 100644 releasenotes/notes/issue-189-fe4024f33e1b5203.yaml

diff --git a/patchwork/tests/test_mboxviews.py b/patchwork/tests/test_mboxviews.py
index 2d6cdc30..8eb3581a 100644
--- a/patchwork/tests/test_mboxviews.py
+++ b/patchwork/tests/test_mboxviews.py
@@ -31,6 +31,7 @@ from patchwork.tests.utils import create_comment
 from patchwork.tests.utils import create_patch
 from patchwork.tests.utils import create_project
 from patchwork.tests.utils import create_person
+from patchwork.tests.utils import create_series_patch
 from patchwork.tests.utils import create_user
 
 
@@ -206,3 +207,26 @@ class MboxCommentPostcriptUnchangedTest(TestCase):
 
         self.assertContains(response, content)
         self.assertNotContains(response, content + '\n')
+
+
+class MboxSeriesDependencies(TestCase):
+
+    def test_patch_with_dependencies(self):
+        patch_a = create_series_patch()
+        patch_b = create_series_patch(series=patch_a.series)
+
+        response = self.client.get('%s?series=*' % reverse(
+            'patch-mbox', args=[patch_b.patch.id]))
+
+        self.assertContains(response, patch_a.patch.content)
+        self.assertContains(response, patch_b.patch.content)
+
+    def test_legacy_patch(self):
+        """Validate a patch with non-existent dependencies raises a 404."""
+        # we're explicitly creating a patch without a series
+        patch = create_patch()
+
+        response = self.client.get('%s?series=*' % reverse(
+            'patch-mbox', args=[patch.id]))
+
+        self.assertEqual(response.status_code, 404)
diff --git a/patchwork/views/patch.py b/patchwork/views/patch.py
index eccb5441..cbd4ec39 100644
--- a/patchwork/views/patch.py
+++ b/patchwork/views/patch.py
@@ -139,6 +139,11 @@ def patch_mbox(request, patch_id):
 
     response = HttpResponse(content_type='text/plain')
     if series_id:
+        if not patch.series.count():
+            raise Http404('Patch does not have an associated series. This is '
+                          'because the patch was processed with an older '
+                          'version of Patchwork. It is not possible to '
+                          'provide dependencies for this patch.')
         response.write(series_patch_to_mbox(patch, series_id))
     else:
         response.write(patch_to_mbox(patch))
diff --git a/releasenotes/notes/issue-189-fe4024f33e1b5203.yaml b/releasenotes/notes/issue-189-fe4024f33e1b5203.yaml
new file mode 100644
index 00000000..ce9fe93c
--- /dev/null
+++ b/releasenotes/notes/issue-189-fe4024f33e1b5203.yaml
@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    If a patch was processed by Patchwork before series support was added, it
+    will not have a series associated with it. As a result, it is not possible
+    to extract the dependencies for that patch from the series. This was not
+    previously handled correctly. A 404 is now raised if this occurs.
-- 
2.17.1