Merge concurrent immutable history correction

Authored-By: OpenAI (GPT-5) <noreply@openai.com>

tests/test_contract.py

@@ -485,7 +485,7 @@ class PublishingTests(unittest.TestCase):
         previous = {
             "baseline-dist": {
                 "path": "/dist", "access": "protected", "artifact": "old-name",
-                "immutable_paths": ["releases"],
+                "immutable_paths": ["dist/releases"],
             }
         }
         with self.assertRaisesRegex(RuntimeError, "cannot become public while reusing protected"):
@@ -594,6 +594,41 @@ class PublishingTests(unittest.TestCase):
             with self.assertRaisesRegex(RuntimeError, "invalid site-publish route history"):
                 deploy.previous_route_contracts(app_dir)
 
+    def test_retired_immutable_history_survives_a_route_move(self):
+        cfg = normalize_site_config(fixture("split-site.yaml"), "baseline.fritzlab.net")
+        artifact = next(item for item in cfg["artifacts"] if item["name"] == "distributions")
+        artifact["cache_rules"] = [
+            rule for rule in artifact["cache_rules"] if rule["path"] != "releases"
+        ]
+        route = next(item for item in cfg["routes"] if item["artifact"] == "distributions")
+        route["path"] = "/"
+        previous = {
+            "baseline-dist": {
+                "path": "/foo", "access": "public", "artifact": "distributions",
+                "immutable_paths": ["foo/releases"],
+            }
+        }
+        with tempfile.TemporaryDirectory() as tmp:
+            root = Path(tmp)
+            app_dir = root / "app"
+            manifests = app_dir / "manifests"
+            app_dir.mkdir()
+            deploy.render_site_manifests(
+                "baseline.fritzlab.net", ROOT, app_dir, manifests, cfg, previous,
+            )
+            following = deploy.previous_route_contracts(app_dir)
+            self.assertEqual(["foo/releases"], following["baseline-dist"]["immutable_paths"])
+            html = root / "html"
+            html.mkdir()
+            first_filters = deploy.retired_immutable_filters(
+                artifact, route, html, previous["baseline-dist"],
+            )
+            following_filters = deploy.retired_immutable_filters(
+                artifact, route, html, following["baseline-dist"],
+            )
+            self.assertEqual(["--exclude", "foo/releases/*"], first_filters)
+            self.assertEqual(first_filters, following_filters)
+
     def test_later_route_immutable_failure_stops_all_mutable_publication(self):
         cfg = normalize_site_config(fixture("split-site.yaml"), "baseline.fritzlab.net")
         with tempfile.TemporaryDirectory() as tmp: