GitHub: handle edge cases with empty responses

swh/lister/github/lister.py

@@ -306,6 +306,10 @@ class GitHubLister(Lister[GitHubListerState, List[Dict[str, Any]]]):
         assert self.lister_obj.id is not None
 
         for repo in page:
+            if not repo:
+                # null repositories in listings happen sometimes...
+                continue
+
             pushed_at_str = repo.get("pushed_at")
             pushed_at: Optional[datetime.datetime] = None
             if pushed_at_str:
@@ -324,6 +328,11 @@ class GitHubLister(Lister[GitHubListerState, List[Dict[str, Any]]]):
             # Don't update internal state when relisting
             return
 
+        if not page:
+            # Sometimes, when you reach the end of the world, GitHub returns an empty
+            # page of repositories
+            return
+
         last_id = page[-1]["id"]
 
         if last_id > self.state.last_seen_id: