Skip checkpoint-equal incremental items

CHANGES.rst

@@ -13,7 +13,9 @@ Unreleased
   legacy file is removed once existing issue/pull backups have resource
   checkpoints (#62).
 - Stop paginating pull requests during incremental backups once the sorted
-  results are older than the active checkpoint.
+  results are at or older than the active checkpoint.
+- Avoid re-fetching discussions and pull requests whose ``updated_at`` exactly
+  matches the active incremental checkpoint.
 - Avoid extra release asset list requests by using asset metadata already
   included in GitHub's releases response.
 - Add ``--token-from-gh`` to read authentication from ``gh auth token``.

github_backup/github_backup.py

@@ -2233,7 +2233,7 @@ def retrieve_discussion_summaries(args, repository, since=None):
             if updated_at and (newest_seen is None or updated_at > newest_seen):
                 newest_seen = updated_at
 
-            if since and updated_at and updated_at < since:
+            if since and updated_at and updated_at <= since:
                 stop = True
                 break
 
@@ -2654,7 +2654,7 @@ def backup_pulls(args, repo_cwd, repository, repos_template):
             newest_pull_update = updated_at
 
     def pull_is_due_for_repository_checkpoint(pull):
-        return not repository_since or pull["updated_at"] >= repository_since
+        return not repository_since or pull["updated_at"] > repository_since
 
     if not args.include_pull_details:
         pull_states = ["open", "closed"]
@@ -2664,18 +2664,18 @@ def backup_pulls(args, repo_cwd, repository, repos_template):
                 args, _pulls_template, query_args=query_args, lazy=True
             ):
                 track_newest_pull_update(pull)
-                if pulls_since and pull["updated_at"] < pulls_since:
+                if pulls_since and pull["updated_at"] <= pulls_since:
                     break
-                if not pulls_since or pull["updated_at"] >= pulls_since:
+                if not pulls_since or pull["updated_at"] > pulls_since:
                     pulls[pull["number"]] = pull
     else:
         for pull in retrieve_data(
             args, _pulls_template, query_args=query_args, lazy=True
         ):
             track_newest_pull_update(pull)
-            if pulls_since and pull["updated_at"] < pulls_since:
+            if pulls_since and pull["updated_at"] <= pulls_since:
                 break
-            if not pulls_since or pull["updated_at"] >= pulls_since:
+            if not pulls_since or pull["updated_at"] > pulls_since:
                 if pull_is_due_for_repository_checkpoint(pull):
                     pulls[pull["number"]] = retrieve_data(
                         args,

tests/test_discussions.py

@@ -50,6 +50,41 @@ def test_retrieve_discussion_summaries_stops_at_incremental_since(create_args):
     )
 
 
+def test_retrieve_discussion_summaries_excludes_checkpoint_timestamp(create_args):
+    args = create_args()
+    repository = {"full_name": "owner/repo"}
+
+    page = {
+        "repository": {
+            "hasDiscussionsEnabled": True,
+            "discussions": {
+                "totalCount": 1,
+                "nodes": [
+                    {
+                        "number": 1,
+                        "title": "already backed up",
+                        "updatedAt": "2026-01-01T00:00:00Z",
+                    },
+                ],
+                "pageInfo": {"hasNextPage": True, "endCursor": "NEXT"},
+            },
+        }
+    }
+
+    with patch(
+        "github_backup.github_backup.retrieve_graphql_data", return_value=page
+    ) as mock_retrieve:
+        summaries, newest, enabled, total = github_backup.retrieve_discussion_summaries(
+            args, repository, since="2026-01-01T00:00:00Z"
+        )
+
+    assert enabled is True
+    assert total == 1
+    assert newest == "2026-01-01T00:00:00Z"
+    assert summaries == []
+    assert mock_retrieve.call_count == 1
+
+
 def test_retrieve_discussion_summaries_disabled_discussions(create_args):
     args = create_args()
     repository = {"full_name": "owner/repo"}

tests/test_pull_incremental_pagination.py

@@ -31,6 +31,52 @@ class MockHTTPResponse:
         return headers
 
 
+def test_backup_pulls_incremental_excludes_checkpoint_timestamp(create_args, tmp_path):
+    args = create_args(include_pulls=True, incremental=True)
+    args.since = "2026-04-26T08:13:46Z"
+    repository = {"full_name": "owner/repo"}
+
+    responses = [
+        MockHTTPResponse([]),
+        MockHTTPResponse(
+            [
+                {
+                    "number": 1,
+                    "title": "already backed up",
+                    "updated_at": "2026-04-26T08:13:46Z",
+                },
+            ],
+            link_header='<https://api.github.com/repos/owner/repo/pulls?per_page=100&state=closed&page=2>; rel="next"',
+        ),
+        MockHTTPResponse(
+            [
+                {
+                    "number": 0,
+                    "title": "older pull on page 2",
+                    "updated_at": "2026-04-25T07:00:00Z",
+                }
+            ]
+        ),
+    ]
+    requests_made = []
+
+    def mock_urlopen(request, *args, **kwargs):
+        requests_made.append(request.get_full_url())
+        return responses[len(requests_made) - 1]
+
+    with patch("github_backup.github_backup.urlopen", side_effect=mock_urlopen):
+        github_backup.backup_pulls(
+            args, tmp_path, repository, "https://api.github.com/repos"
+        )
+
+    assert len(requests_made) == 2
+    assert "state=open" in requests_made[0]
+    assert "state=closed" in requests_made[1]
+    assert all("page=2" not in url for url in requests_made)
+    assert not os.path.exists(tmp_path / "pulls" / "1.json")
+    assert not os.path.exists(tmp_path / "pulls" / "0.json")
+
+
 def test_backup_pulls_incremental_stops_before_fetching_old_pages(
     create_args, tmp_path
 ):