add compatibility field for landing path

landoapi/models/landing_job.py

@@ -137,6 +137,23 @@ class LandingJob(Base):
     def landing_path(self) -> list[tuple[int, int]]:
         return [(revision.revision_id, revision.diff_id) for revision in self.revisions]
 
+    @property
+    def landing_path_compat(self):
+        """Return landing path based on associated revisions or legacy fields."""
+        if self.revisions:
+            return [
+                {
+                    "revision_id": "D{}".format(revision_id),
+                    "diff_id": diff_id,
+                }
+                for revision_id, diff_id in self.landing_path
+            ]
+        else:
+            return [
+                {"revision_id": "D{}".format(r), "diff_id": self.revision_to_diff_id[r]}
+                for r in self.revision_order
+            ]
+
     @property
     def head_revision(self) -> str:
         """Human-readable representation of the branch head's Phabricator revision ID."""
@@ -313,13 +330,7 @@ def serialize(self) -> dict[str, Any]:
         return {
             "id": self.id,
             "status": self.status.value,
-            "landing_path": [
-                {
-                    "revision_id": "D{}".format(revision.revision_id),
-                    "diff_id": revision.diff_id,
-                }
-                for revision in self.revisions
-            ],
+            "landing_path": self.landing_path_compat,
             "error_breakdown": self.error_breakdown,
             "details": (
                 self.error or self.landed_commit_id