Remove repo.is_empty from codebase

Replace with repo.head_is_unborn:

- repo.is_empty - repo has no commits, no extra config, and is on an
  unborn branch with the default branch name
- repo.head_is_unborn - repo HEAD points at an unborn branch

The second one is what we actually care about - using the first one
means we can get false negatives (the no-commits codepath won't trigger
because of some other minor change in the repo)

kart/data.py

@@ -32,10 +32,7 @@ def data(ctx, **kwargs):
 def data_ls(ctx, output_format, refish):
     """List all of the datasets in the Kart repository"""
     repo = ctx.obj.get_repo(allowed_states=KartRepoState.ALL_STATES)
-    if repo.is_empty:
-        ds_paths = []
-    else:
-        ds_paths = [ds.path for ds in repo.datasets(refish)]
+    ds_paths = list(repo.datasets(refish).all_paths())
 
     if output_format == "text":
         if ds_paths:
@@ -79,10 +76,7 @@ def data_rm(ctx, message, output_format, datasets):
         raise click.UsageError("Specify a dataset to delete: eg `kart data rm DATASET`")
 
     repo = ctx.obj.get_repo()
-    if repo.is_empty:
-        existing_ds_paths = set()
-    else:
-        existing_ds_paths = set(ds.path for ds in repo.datasets())
+    existing_ds_paths = set(repo.datasets().all_paths())
 
     for ds_path in datasets:
         if ds_path not in existing_ds_paths:

tests/conftest.py

@@ -348,7 +348,7 @@ def _data_imported(archive, source_gpkg, table):
                 assert r.exit_code == 0, r.stderr
 
                 repo = KartRepo(import_path)
-                assert repo.is_empty
+                assert repo.head_is_unborn
                 repo.free()
                 del repo
 

tests/test_init.py

@@ -650,7 +650,7 @@ def test_init_import(
 
         repo = KartRepo(repo_path)
         assert not repo.is_bare
-        assert not repo.is_empty
+        assert not repo.head_is_unborn
 
         assert repo.head.name == "refs/heads/main"
         assert repo.head.shorthand == "main"
@@ -772,7 +772,7 @@ def test_init_import_name_clash(data_archive, cli_runner):
 
         repo = KartRepo(repo_path)
         assert not repo.is_bare
-        assert not repo.is_empty
+        assert not repo.head_is_unborn
 
         # working copy exists
         wc = repo_path / "editing.gpkg"

tests/test_remote.py

@@ -125,7 +125,7 @@ def test_clone(
         print("git config file:", r.decode("utf-8").splitlines())
 
         repo = KartRepo(repo_path)
-        assert not repo.is_empty
+        assert not repo.head_is_unborn
         assert repo.head.name == f"refs/heads/{branch_name}"
 
         if branch_ref == "HEAD^":

tests/test_structure.py

@@ -175,12 +175,12 @@ def _benchmark_reset(*args, **kwargs):
             assert r.exit_code == 0, r
 
             repo = KartRepo(repo_path)
-            assert repo.is_empty
+            assert repo.head_is_unborn
 
             r = cli_runner.invoke(["import", str(data / source_gpkg), table])
             assert r.exit_code == 0, r
 
-            assert not repo.is_empty
+            assert not repo.head_is_unborn
             assert repo.head.name == "refs/heads/main"
             assert repo.head.shorthand == "main"
 
@@ -889,7 +889,7 @@ def test_import_multiple(data_archive, chdir, cli_runner, tmp_path):
         assert r.exit_code == 0, r
 
     repo = KartRepo(repo_path)
-    assert repo.is_empty
+    assert repo.head_is_unborn
 
     LAYERS = (
         ("gpkg-points", "nz-pa-points-topo-150k.gpkg", H.POINTS.LAYER),
@@ -1033,7 +1033,7 @@ def test_fast_import(data_archive, tmp_path, cli_runner, chdir):
 
             fast_import.fast_import_tables(repo, [source], from_commit=None)
 
-            assert not repo.is_empty
+            assert not repo.head_is_unborn
             assert repo.head.name == "refs/heads/main"
             assert repo.head.shorthand == "main"
 

tests/test_working_copy_postgis.py

@@ -258,7 +258,7 @@ def test_postgis_wc_with_long_index_name(
 
             repo = KartRepo(repo_path)
             assert not repo.is_bare
-            assert not repo.is_empty
+            assert not repo.head_is_unborn
 
             table_wc = repo.working_copy.tabular
             insp = inspect(table_wc.engine)