Merge ~xnox/launchpad:fixup-i18n-index-publish into launchpad:master

[Dimitri John Ledkov]

soyuz: fix up removal of stale i18n/Index upon removal

During qastaging testing it was discovered that i18n/Index publishing
correctly honors publish_i18n_index setting for freshly created suites
in an archive. But existing archives incorrectly left stale i18n/Index
on disk (whilst scheduling byhash symlink removal).

QA Testing:
* create a new archive on qastaging
* publish it once
* verify i18n/Index is published with byhash link to it
* toggle publish_i18n_index off
* publish it again
* verify i18n/Index is gone straight away
* verify deathrow 24h later removed byhash link to it as well

Fixes: 5f90943b2f ("soyuz: Add toggle to turn off I18n/Index publishing")

[Guruprasad (lgp171188)]

LGTM 👍 As discussed already, I will request a review + approval from William as well before we merge this.

review: Approve

[William Grant (wgrant)]

review: Approve (code)

[Dimitri John Ledkov (xnox)]

And had to fix up the test case further - as it was not setting the publish_i18n_index flag on the wrong distro series. And the test cases worked before, because index is never published if it references no translation files. Thus fixed up test case to add empty Translation-en to cause index generation; and flipping the publish_i18n_index flag on the right distro series.

So this actually tests the flag properly now, including flipping the state of it.

This now also addresses wgrant review comments above.

review: Approve

[Dimitri John Ledkov (xnox)]

rebased and squashed.

diff --git a/lib/lp/archivepublisher/publishing.py b/lib/lp/archivepublisher/publishing.py
index 165c030..bddf01e 100644
--- a/lib/lp/archivepublisher/publishing.py
+++ b/lib/lp/archivepublisher/publishing.py
@@ -1682,12 +1682,16 @@ class Publisher:
             # Schedule i18n files for inclusion in the Release file.
             all_series_files.add(os.path.join(i18n_subpath, i18n_file))
 
+        i18n_file_name = os.path.join(i18n_dir, "Index")
         if distroseries.publish_i18n_index:
-            with open(os.path.join(i18n_dir, "Index"), "wb") as f:
+            with open(i18n_file_name, "wb") as f:
                 i18n_index.dump(f, "utf-8")
 
             # Schedule this for inclusion in the Release file.
             all_series_files.add(os.path.join(component, "i18n", "Index"))
+        else:
+            if os.path.exists(i18n_file_name):
+                os.unlink(i18n_file_name)
 
     def _readIndexFileHashes(
         self, suite, file_name, subpath=None, real_file_name=None
diff --git a/lib/lp/archivepublisher/tests/test_publisher.py b/lib/lp/archivepublisher/tests/test_publisher.py
index 91a3c0b..70c9c70 100644
--- a/lib/lp/archivepublisher/tests/test_publisher.py
+++ b/lib/lp/archivepublisher/tests/test_publisher.py
@@ -2859,7 +2859,25 @@ class TestPublisher(TestPublisherBase):
             self.config.distsroot, "breezy-autotest", "main", "i18n"
         )
 
-        self.ubuntu["breezy-autotest"].publish_i18n_index = False
+        # Write compressed versions of a zero-length Translation-en file.
+        translation_en_index = RepositoryIndexFile(
+            os.path.join(i18n_root, "Translation-en"),
+            self.config.temproot,
+            self.ubuntutest["breezy-autotest"].index_compressors,
+        )
+        translation_en_index.close()
+
+        # First publish i18n/Index (status quo)
+        publisher._writeSuiteI18n(
+            self.ubuntutest["breezy-autotest"],
+            PackagePublishingPocket.RELEASE,
+            "main",
+            set(),
+        )
+
+        self.assertTrue(os.path.exists(os.path.join(i18n_root, "Index")))
+
+        self.ubuntutest["breezy-autotest"].publish_i18n_index = False
 
         publisher._writeSuiteI18n(
             self.ubuntutest["breezy-autotest"],
@@ -2868,6 +2886,7 @@ class TestPublisher(TestPublisherBase):
             set(),
         )
 
+        # Ensure it is removed, if previously existed
         self.assertFalse(os.path.exists(os.path.join(i18n_root, "Index")))
 
     def testReadIndexFileHashesCompression(self):