Merge pull request #100 from mikedarcy/master

Allow bag in-place on empty directories

Author: acdha

bagit.py

@@ -1144,6 +1144,10 @@ def make_manifests(data_dir, processes, algorithms=DEFAULT_CHECKSUMS, encoding='
     byte_value_set = set(total_bytes.values())
     file_count_set = set(num_files.values())
 
+    # allow a bag with an empty payload
+    if not byte_value_set and not file_count_set:
+        return 0, 0
+
     if len(file_count_set) != 1:
         raise RuntimeError(_('Expected the same number of files for each checksum'))
 

test.py

@@ -516,6 +516,22 @@ def test_make_bag_sha512_manifest(self):
     def test_make_bag_unknown_algorithm(self):
         self.assertRaises(ValueError, bagit.make_bag, self.tmpdir, checksum=['not-really-a-name'])
 
+    def test_make_bag_with_empty_directory(self):
+        tmpdir = tempfile.mkdtemp()
+        try:
+            bagit.make_bag(tmpdir)
+        finally:
+            shutil.rmtree(tmpdir)
+
+    def test_make_bag_with_empty_directory_tree(self):
+        tmpdir = tempfile.mkdtemp()
+        path = j(tmpdir, "test1", "test2")
+        try:
+            os.makedirs(path)
+            bagit.make_bag(tmpdir)
+        finally:
+            shutil.rmtree(tmpdir)
+
     def test_make_bag_with_bogus_directory(self):
         bogus_directory = os.path.realpath('this-directory-does-not-exist')