Fix push_to_hub by not calling create_branch if branch exists (#7069)

* Fix push_to_hub by not calling create_branch if branch exists

* Fix push_to_hub by not calling create_branch if branch exists

* Reword comment

* Fix push_to_hub by not calling create_branch if PR ref

* Update test

Author: albertvillanova

src/datasets/arrow_dataset.py

@@ -5677,7 +5677,8 @@ def push_to_hub(
         )
         repo_id = repo_url.repo_id
 
-        if revision is not None:
+        if revision is not None and not revision.startswith("refs/pr/"):
+            # We do not call create_branch for a PR reference: 400 Bad Request
             api.create_branch(repo_id, branch=revision, token=token, repo_type="dataset", exist_ok=True)
 
         if not data_dir:

src/datasets/dataset_dict.py

@@ -1708,7 +1708,8 @@ def push_to_hub(
         )
         repo_id = repo_url.repo_id
 
-        if revision is not None:
+        if revision is not None and not revision.startswith("refs/pr/"):
+            # We do not call create_branch for a PR reference: 400 Bad Request
             api.create_branch(repo_id, branch=revision, token=token, repo_type="dataset", exist_ok=True)
 
         if not data_dir:

tests/test_hub.py

@@ -66,9 +66,8 @@ def test_convert_to_parquet(temporary_repo, hf_api, hf_token, ci_hub_config, ci_
                         _ = convert_to_parquet(repo_id, token=hf_token, trust_remote_code=True)
     # mock_create_branch
     assert mock_create_branch.called
-    assert mock_create_branch.call_count == 2
-    for call_args, expected_branch in zip(mock_create_branch.call_args_list, ["refs/pr/1", "script"]):
-        assert call_args.kwargs.get("branch") == expected_branch
+    assert mock_create_branch.call_count == 1
+    assert mock_create_branch.call_args.kwargs.get("branch") == "script"
     # mock_create_commit
     assert mock_create_commit.called
     assert mock_create_commit.call_count == 2