diff --git a/swh/loader/package/tests/test_pypi.py b/swh/loader/package/tests/test_pypi.py
index 1937a2c..c4e5636 100644
--- a/swh/loader/package/tests/test_pypi.py
+++ b/swh/loader/package/tests/test_pypi.py
@@ -1,595 +1,652 @@
 # Copyright (C) 2019 The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import os
 
 from os import path
 
 import pytest
 
 from unittest.mock import patch
 
 from swh.core.tarball import uncompress
 from swh.model.hashutil import hash_to_bytes
 from swh.loader.package.pypi import (
     PyPILoader, pypi_api_url, author, extract_intrinsic_metadata
 )
 from swh.loader.package.tests.common import (
     check_snapshot, DATADIR, check_metadata_paths
 )
 
 from swh.loader.package.tests.conftest import local_get_factory
 
 
 def test_author_basic():
     data = {
         'author': "i-am-groot",
         'author_email': 'iam@groot.org',
     }
     actual_author = author(data)
 
     expected_author = {
         'fullname': b'i-am-groot <iam@groot.org>',
         'name': b'i-am-groot',
         'email': b'iam@groot.org',
     }
 
     assert actual_author == expected_author
 
 
 def test_author_empty_email():
     data = {
         'author': 'i-am-groot',
         'author_email': '',
     }
     actual_author = author(data)
 
     expected_author = {
         'fullname': b'i-am-groot',
         'name': b'i-am-groot',
         'email': b'',
     }
 
     assert actual_author == expected_author
 
 
 def test_author_empty_name():
     data = {
         'author': "",
         'author_email': 'iam@groot.org',
     }
     actual_author = author(data)
 
     expected_author = {
         'fullname': b' <iam@groot.org>',
         'name': b'',
         'email': b'iam@groot.org',
     }
 
     assert actual_author == expected_author
 
 
 def test_author_malformed():
     data = {
         'author': "['pierre', 'paul', 'jacques']",
         'author_email': None,
     }
 
     actual_author = author(data)
 
     expected_author = {
         'fullname': b"['pierre', 'paul', 'jacques']",
         'name': b"['pierre', 'paul', 'jacques']",
         'email': None,
     }
 
     assert actual_author == expected_author
 
 
 def test_author_malformed_2():
     data = {
         'author': '[marie, jeanne]',
         'author_email': '[marie@some, jeanne@thing]',
     }
 
     actual_author = author(data)
 
     expected_author = {
         'fullname': b'[marie, jeanne] <[marie@some, jeanne@thing]>',
         'name': b'[marie, jeanne]',
         'email': b'[marie@some, jeanne@thing]',
     }
 
     assert actual_author == expected_author
 
 
 def test_author_malformed_3():
     data = {
         'author': '[marie, jeanne, pierre]',
         'author_email': '[marie@somewhere.org, jeanne@somewhere.org]',
     }
 
     actual_author = author(data)
 
     expected_author = {
         'fullname': b'[marie, jeanne, pierre] <[marie@somewhere.org, jeanne@somewhere.org]>',  # noqa
         'name': b'[marie, jeanne, pierre]',
         'email': b'[marie@somewhere.org, jeanne@somewhere.org]',
     }
 
     actual_author == expected_author
 
 
 # configuration error #
 
 def test_badly_configured_loader_raise(monkeypatch):
     """Badly configured loader should raise"""
     monkeypatch.delenv('SWH_CONFIG_FILENAME', raising=False)
     with pytest.raises(ValueError) as e:
         PyPILoader(url='some-url')
 
     assert 'Misconfiguration' in e.value.args[0]
 
 
 def test_pypi_api_url():
     """Compute pypi api url from the pypi project url should be ok"""
     url = pypi_api_url('https://pypi.org/project/requests')
     assert url == 'https://pypi.org/pypi/requests/json'
 
 
 @pytest.mark.fs
 def test_extract_intrinsic_metadata(tmp_path):
     """Parsing existing archive's PKG-INFO should yield results"""
     uncompressed_archive_path = str(tmp_path)
     archive_path = path.join(
         DATADIR, 'files.pythonhosted.org', '0805nexter-1.1.0.zip')
     uncompress(archive_path, dest=uncompressed_archive_path)
 
     actual_metadata = extract_intrinsic_metadata(uncompressed_archive_path)
     expected_metadata = {
         'metadata_version': '1.0',
         'name': '0805nexter',
         'version': '1.1.0',
         'summary': 'a simple printer of nested lest',
         'home_page': 'http://www.hp.com',
         'author': 'hgtkpython',
         'author_email': '2868989685@qq.com',
         'platforms': ['UNKNOWN'],
     }
 
     assert actual_metadata == expected_metadata
 
 
 @pytest.mark.fs
 def test_extract_intrinsic_metadata_failures(tmp_path):
     """Parsing inexistant path/archive/PKG-INFO yield None"""
     # inexistant first level path
     assert extract_intrinsic_metadata('/something-inexistant') == {}
     # inexistant second level path (as expected by pypi archives)
     assert extract_intrinsic_metadata(tmp_path) == {}
     # inexistant PKG-INFO within second level path
     existing_path_no_pkginfo = str(tmp_path / 'something')
     os.mkdir(existing_path_no_pkginfo)
     assert extract_intrinsic_metadata(tmp_path) == {}
 
 
 # LOADER SCENARIO #
 
 # "edge" cases (for the same origin) #
 
 
 # no release artifact:
 # {visit full, status: uneventful, no contents, etc...}
 local_get_missing_all = local_get_factory(ignore_urls=[
     'https://files.pythonhosted.org/packages/ec/65/c0116953c9a3f47de89e71964d6c7b0c783b01f29fa3390584dbf3046b4d/0805nexter-1.1.0.zip',  # noqa
     'https://files.pythonhosted.org/packages/c4/a0/4562cda161dc4ecbbe9e2a11eb365400c0461845c5be70d73869786809c4/0805nexter-1.2.0.zip',  # noqa
 ])
 
 
 def test_no_release_artifact(swh_config, local_get_missing_all):
     """Load a pypi project with all artifacts missing ends up with no snapshot
 
     """
     url = 'https://pypi.org/project/0805nexter'
     loader = PyPILoader(url)
 
     actual_load_status = loader.load()
     assert actual_load_status['status'] == 'uneventful'
 
     stats = loader.storage.stat_counters()
     assert {
         'content': 0,
         'directory': 0,
         'origin': 1,
         'origin_visit': 1,
         'person': 0,
         'release': 0,
         'revision': 0,
         'skipped_content': 0,
         'snapshot': 1,
     } == stats
 
     origin_visit = next(loader.storage.origin_visit_get(url))
     assert origin_visit['status'] == 'partial'
 
 
 # problem during loading:
 # {visit: partial, status: uneventful, no snapshot}
 
 
 def test_release_with_traceback(swh_config):
     url = 'https://pypi.org/project/0805nexter'
     with patch('swh.loader.package.pypi.PyPILoader.get_default_release',
                side_effect=ValueError('Problem')):
         loader = PyPILoader(url)
 
         actual_load_status = loader.load()
         assert actual_load_status['status'] == 'failed'
 
         stats = loader.storage.stat_counters()
 
         assert {
             'content': 0,
             'directory': 0,
             'origin': 1,
             'origin_visit': 1,
             'person': 0,
             'release': 0,
             'revision': 0,
             'skipped_content': 0,
             'snapshot': 0,
         } == stats
 
     origin_visit = next(loader.storage.origin_visit_get(url))
     assert origin_visit['status'] == 'partial'
 
 
 # problem during loading: failure early enough in between swh contents...
 # some contents (contents, directories, etc...) have been written in storage
 # {visit: partial, status: eventful, no snapshot}
 
 # problem during loading: failure late enough we can have snapshots (some
 # revisions are written in storage already)
 # {visit: partial, status: eventful, snapshot}
 
 # "normal" cases (for the same origin) #
 
 
 local_get_missing_one = local_get_factory(ignore_urls=[
     'https://files.pythonhosted.org/packages/ec/65/c0116953c9a3f47de89e71964d6c7b0c783b01f29fa3390584dbf3046b4d/0805nexter-1.1.0.zip',  # noqa
 ])
 
 # some missing release artifacts:
 # {visit partial, status: eventful, 1 snapshot}
 
 
 def test_revision_metadata_structure(swh_config, local_get):
     url = 'https://pypi.org/project/0805nexter'
     loader = PyPILoader(url)
 
     actual_load_status = loader.load()
     assert actual_load_status['status'] == 'eventful'
 
     expected_revision_id = hash_to_bytes(
         'e445da4da22b31bfebb6ffc4383dbf839a074d21')
     revision = list(loader.storage.revision_get([expected_revision_id]))[0]
 
     assert revision is not None
 
     check_metadata_paths(revision['metadata'], paths=[
         ('intrinsic.tool', str),
         ('intrinsic.raw', dict),
         ('extrinsic.provider', str),
         ('extrinsic.when', str),
         ('extrinsic.raw', dict),
         ('original_artifact.filename', str),
         ('original_artifact.length', int),
         ('original_artifact.checksums', dict),
     ])
 
 
-def test_release_with_missing_artifact(swh_config, local_get_missing_one):
+def test_visit_with_missing_artifact(swh_config, local_get_missing_one):
     """Load a pypi project with some missing artifacts ends up with 1 snapshot
 
     """
     url = 'https://pypi.org/project/0805nexter'
     loader = PyPILoader(url)
 
     actual_load_status = loader.load()
     assert actual_load_status['status'] == 'eventful'
 
     stats = loader.storage.stat_counters()
     assert {
         'content': 3,
         'directory': 2,
         'origin': 1,
         'origin_visit': 1,
         'person': 1,
         'release': 0,
         'revision': 1,
         'skipped_content': 0,
         'snapshot': 1
     } == stats
 
     expected_contents = map(hash_to_bytes, [
         '405859113963cb7a797642b45f171d6360425d16',
         'e5686aa568fdb1d19d7f1329267082fe40482d31',
         '83ecf6ec1114fd260ca7a833a2d165e71258c338',
     ])
 
     assert list(loader.storage.content_missing_per_sha1(expected_contents))\
         == []
 
     expected_dirs = map(hash_to_bytes, [
         'b178b66bd22383d5f16f4f5c923d39ca798861b4',
         'c3a58f8b57433a4b56caaa5033ae2e0931405338',
     ])
 
     assert list(loader.storage.directory_missing(expected_dirs)) == []
 
     # {revision hash: directory hash}
     expected_revs = {
         hash_to_bytes('e445da4da22b31bfebb6ffc4383dbf839a074d21'): hash_to_bytes('b178b66bd22383d5f16f4f5c923d39ca798861b4'),  # noqa
     }
     assert list(loader.storage.revision_missing(expected_revs)) == []
 
     expected_branches = {
         'releases/1.2.0': {
             'target': 'e445da4da22b31bfebb6ffc4383dbf839a074d21',
             'target_type': 'revision',
         },
         'HEAD': {
             'target': 'releases/1.2.0',
             'target_type': 'alias',
         },
     }
 
     expected_snapshot = {
         'id': 'dd0e4201a232b1c104433741dbf45895b8ac9355',
         'branches': expected_branches,
     }
     check_snapshot(expected_snapshot, storage=loader.storage)
 
     origin_visit = next(loader.storage.origin_visit_get(url))
     assert origin_visit['status'] == 'partial'
 
 
-def test_release_artifact_no_prior_visit(swh_config, local_get):
+def test_visit_with_1_release_artifact(swh_config, local_get):
     """With no prior visit, load a pypi project ends up with 1 snapshot
 
     """
     url = 'https://pypi.org/project/0805nexter'
     loader = PyPILoader(url)
 
     actual_load_status = loader.load()
     assert actual_load_status['status'] == 'eventful'
 
     stats = loader.storage.stat_counters()
     assert {
         'content': 6,
         'directory': 4,
         'origin': 1,
         'origin_visit': 1,
         'person': 1,
         'release': 0,
         'revision': 2,
         'skipped_content': 0,
         'snapshot': 1
     } == stats
 
     expected_contents = map(hash_to_bytes, [
         'a61e24cdfdab3bb7817f6be85d37a3e666b34566',
         '938c33483285fd8ad57f15497f538320df82aeb8',
         'a27576d60e08c94a05006d2e6d540c0fdb5f38c8',
         '405859113963cb7a797642b45f171d6360425d16',
         'e5686aa568fdb1d19d7f1329267082fe40482d31',
         '83ecf6ec1114fd260ca7a833a2d165e71258c338',
     ])
 
     assert list(loader.storage.content_missing_per_sha1(expected_contents))\
         == []
 
     expected_dirs = map(hash_to_bytes, [
         '05219ba38bc542d4345d5638af1ed56c7d43ca7d',
         'cf019eb456cf6f78d8c4674596f1c9a97ece8f44',
         'b178b66bd22383d5f16f4f5c923d39ca798861b4',
         'c3a58f8b57433a4b56caaa5033ae2e0931405338',
     ])
 
     assert list(loader.storage.directory_missing(expected_dirs)) == []
 
     # {revision hash: directory hash}
     expected_revs = {
         hash_to_bytes('4c99891f93b81450385777235a37b5e966dd1571'): hash_to_bytes('05219ba38bc542d4345d5638af1ed56c7d43ca7d'),  # noqa
         hash_to_bytes('e445da4da22b31bfebb6ffc4383dbf839a074d21'): hash_to_bytes('b178b66bd22383d5f16f4f5c923d39ca798861b4'),  # noqa
     }
     assert list(loader.storage.revision_missing(expected_revs)) == []
 
     expected_branches = {
         'releases/1.1.0': {
             'target': '4c99891f93b81450385777235a37b5e966dd1571',
             'target_type': 'revision',
         },
         'releases/1.2.0': {
             'target': 'e445da4da22b31bfebb6ffc4383dbf839a074d21',
             'target_type': 'revision',
         },
         'HEAD': {
             'target': 'releases/1.2.0',
             'target_type': 'alias',
         },
     }
 
     expected_snapshot = {
         'id': 'ba6e158ada75d0b3cfb209ffdf6daa4ed34a227a',
         'branches': expected_branches,
     }
     check_snapshot(expected_snapshot, loader.storage)
 
     origin_visit = next(loader.storage.origin_visit_get(url))
     assert origin_visit['status'] == 'full'
 
 
-# release artifact, new artifact
-# {visit full, status full, new snapshot with shared history as prior snapshot}
-def test_release_artifact_incremental_visit(swh_config, local_get_visits):
-    """With prior visit, 2nd load will result with a different snapshot
+def test_multiple_visits_with_no_change(swh_config, local_get):
+    """Multiple visits with no changes results in 1 same snapshot
 
-    with some shared history
+    """
+    url = 'https://pypi.org/project/0805nexter'
+    loader = PyPILoader(url)
+
+    actual_load_status = loader.load()
+    assert actual_load_status['status'] == 'eventful'
+
+    stats = loader.storage.stat_counters()
+    assert {
+        'content': 6,
+        'directory': 4,
+        'origin': 1,
+        'origin_visit': 1,
+        'person': 1,
+        'release': 0,
+        'revision': 2,
+        'skipped_content': 0,
+        'snapshot': 1
+    } == stats
+
+    expected_branches = {
+        'releases/1.1.0': {
+            'target': '4c99891f93b81450385777235a37b5e966dd1571',
+            'target_type': 'revision',
+        },
+        'releases/1.2.0': {
+            'target': 'e445da4da22b31bfebb6ffc4383dbf839a074d21',
+            'target_type': 'revision',
+        },
+        'HEAD': {
+            'target': 'releases/1.2.0',
+            'target_type': 'alias',
+        },
+    }
+
+    snapshot_id = 'ba6e158ada75d0b3cfb209ffdf6daa4ed34a227a'
+    expected_snapshot = {
+        'id': snapshot_id,
+        'branches': expected_branches,
+    }
+    check_snapshot(expected_snapshot, loader.storage)
+
+    origin_visit = next(loader.storage.origin_visit_get(url))
+    assert origin_visit['status'] == 'full'
+
+    actual_load_status2 = loader.load()
+    assert actual_load_status2['status'] == 'uneventful'
+
+    stats2 = loader.storage.stat_counters()
+    expected_stats2 = stats.copy()
+    expected_stats2['origin_visit'] = 1 + 1
+    assert expected_stats2 == stats2
+
+    # same snapshot
+    actual_snapshot_id = origin_visit['snapshot']['id']
+    assert actual_snapshot_id == hash_to_bytes(snapshot_id)
+
+
+def test_incremental_visit(swh_config, local_get_visits):
+    """With prior visit, 2nd load will result with a different snapshot
 
     """
     url = 'https://pypi.org/project/0805nexter'
     loader = PyPILoader(url)
 
     visit1_actual_load_status = loader.load()
     visit1_stats = loader.storage.stat_counters()
     assert visit1_actual_load_status['status'] == 'eventful'
     origin_visit1 = next(loader.storage.origin_visit_get(url))
     assert origin_visit1['status'] == 'full'
 
     assert {
         'content': 6,
         'directory': 4,
         'origin': 1,
         'origin_visit': 1,
         'person': 1,
         'release': 0,
         'revision': 2,
         'skipped_content': 0,
         'snapshot': 1
     } == visit1_stats
 
     # Reset internal state
     loader._info = None
 
     visit2_actual_load_status = loader.load()
     visit2_stats = loader.storage.stat_counters()
 
     assert visit2_actual_load_status['status'] == 'eventful'
     visits = list(loader.storage.origin_visit_get(url))
     assert len(visits) == 2
     assert visits[1]['status'] == 'full'
 
     assert {
         'content': 6 + 1,     # 1 more content
         'directory': 4 + 2,   # 2 more directories
         'origin': 1,
         'origin_visit': 1 + 1,
         'person': 1,
         'release': 0,
         'revision': 2 + 1,    # 1 more revision
         'skipped_content': 0,
         'snapshot': 1 + 1,    # 1 more snapshot
     } == visit2_stats
 
     expected_contents = map(hash_to_bytes, [
         'a61e24cdfdab3bb7817f6be85d37a3e666b34566',
         '938c33483285fd8ad57f15497f538320df82aeb8',
         'a27576d60e08c94a05006d2e6d540c0fdb5f38c8',
         '405859113963cb7a797642b45f171d6360425d16',
         'e5686aa568fdb1d19d7f1329267082fe40482d31',
         '83ecf6ec1114fd260ca7a833a2d165e71258c338',
         '92689fa2b7fb4d4fc6fb195bf73a50c87c030639'
     ])
 
     assert list(loader.storage.content_missing_per_sha1(expected_contents))\
         == []
 
     expected_dirs = map(hash_to_bytes, [
         '05219ba38bc542d4345d5638af1ed56c7d43ca7d',
         'cf019eb456cf6f78d8c4674596f1c9a97ece8f44',
         'b178b66bd22383d5f16f4f5c923d39ca798861b4',
         'c3a58f8b57433a4b56caaa5033ae2e0931405338',
         'e226e7e4ad03b4fc1403d69a18ebdd6f2edd2b3a',
         '52604d46843b898f5a43208045d09fcf8731631b',
 
     ])
 
     assert list(loader.storage.directory_missing(expected_dirs)) == []
 
     # {revision hash: directory hash}
     expected_revs = {
         hash_to_bytes('4c99891f93b81450385777235a37b5e966dd1571'): hash_to_bytes('05219ba38bc542d4345d5638af1ed56c7d43ca7d'),  # noqa
         hash_to_bytes('e445da4da22b31bfebb6ffc4383dbf839a074d21'): hash_to_bytes('b178b66bd22383d5f16f4f5c923d39ca798861b4'),  # noqa
         hash_to_bytes('51247143b01445c9348afa9edfae31bf7c5d86b1'): hash_to_bytes('e226e7e4ad03b4fc1403d69a18ebdd6f2edd2b3a'),  # noqa
     }
 
     assert list(loader.storage.revision_missing(expected_revs)) == []
 
     expected_branches = {
         'releases/1.1.0': {
             'target': '4c99891f93b81450385777235a37b5e966dd1571',
             'target_type': 'revision',
         },
         'releases/1.2.0': {
             'target': 'e445da4da22b31bfebb6ffc4383dbf839a074d21',
             'target_type': 'revision',
         },
         'releases/1.3.0': {
             'target': '51247143b01445c9348afa9edfae31bf7c5d86b1',
             'target_type': 'revision',
         },
         'HEAD': {
             'target': 'releases/1.3.0',
             'target_type': 'alias',
         },
     }
     expected_snapshot = {
         'id': '2e5149a7b0725d18231a37b342e9b7c4e121f283',
         'branches': expected_branches,
     }
 
     check_snapshot(expected_snapshot, loader.storage)
 
     origin_visit = list(loader.storage.origin_visit_get(url))[-1]
     assert origin_visit['status'] == 'full'
 
     urls = [
         m.url for m in local_get_visits.request_history
         if m.url.startswith('https://files.pythonhosted.org')
     ]
     # visited each artifact once across 2 visits
     assert len(urls) == len(set(urls))
 
 
 # release artifact, no new artifact
 # {visit full, status uneventful, same snapshot as before}
 
 # release artifact, old artifact with different checksums
 # {visit full, status full, new snapshot with shared history and some new
 # different history}
 
 # release with multiple sdist artifacts per pypi "version"
 # snapshot branch output is different
 
 def test_visit_1_release_with_2_artifacts(swh_config, local_get):
     """With no prior visit, load a pypi project ends up with 1 snapshot
 
     """
     url = 'https://pypi.org/project/nexter'
     loader = PyPILoader(url)
 
     actual_load_status = loader.load()
     assert actual_load_status['status'] == 'eventful'
 
     expected_branches = {
         'releases/1.1.0/nexter-1.1.0.zip': {
             'target': '4c99891f93b81450385777235a37b5e966dd1571',
             'target_type': 'revision',
         },
         'releases/1.1.0/nexter-1.1.0.tar.gz': {
             'target': '0bf88f5760cca7665d0af4d6575d9301134fe11a',
             'target_type': 'revision',
         },
     }
 
     expected_snapshot = {
         'id': 'a27e638a4dad6fbfa273c6ebec1c4bf320fb84c6',
         'branches': expected_branches,
     }
     check_snapshot(expected_snapshot, loader.storage)
 
     origin_visit = next(loader.storage.origin_visit_get(url))
     assert origin_visit['status'] == 'full'