Make auth = basic the default again (#477)

Fix #461
Fix #457

CHANGELOG.rst

@@ -9,6 +9,13 @@ Package maintainers and users who have to manually update their installation
 may want to subscribe to `GitHub's tag feed
 <https://github.com/pimutils/vdirsyncer/tags.atom>`_.
 
+Version 0.11.3
+==============
+
+- Default value of ``auth`` parameter was changed from ``guess`` to ``basic``
+  to resolve issues with the Apple Calendar Server (:gh:`457`) and improve
+  performance. See :gh:`461`.
+
 Version 0.11.2
 ==============
 

tests/storage/test_http.py

@@ -83,7 +83,9 @@ def test_readonly_param():
 def test_prepare_auth():
     assert prepare_auth(None, '', '') is None
 
+    assert prepare_auth(None, 'user', 'pwd') == ('user', 'pwd')
     assert prepare_auth('basic', 'user', 'pwd') == ('user', 'pwd')
+
     with pytest.raises(ValueError) as excinfo:
         assert prepare_auth('basic', '', 'pwd')
     assert 'you need to specify username and password' in \
@@ -99,17 +101,16 @@ def test_prepare_auth():
     assert 'unknown authentication method' in str(excinfo.value).lower()
 
 
-@pytest.mark.parametrize('auth', (None, 'guess'))
+def test_prepare_auth_guess(monkeypatch):
-def test_prepare_auth_guess(monkeypatch, auth):
     import requests_toolbelt.auth.guess
 
-    assert isinstance(prepare_auth(auth, 'user', 'pwd'),
+    assert isinstance(prepare_auth('guess', 'user', 'pwd'),
                       requests_toolbelt.auth.guess.GuessAuth)
 
     monkeypatch.delattr(requests_toolbelt.auth.guess, 'GuessAuth')
 
     with pytest.raises(UserError) as excinfo:
-        prepare_auth(auth, 'user', 'pwd')
+        prepare_auth('guess', 'user', 'pwd')
 
     assert 'requests_toolbelt is too old' in str(excinfo.value).lower()
 

vdirsyncer/storage/http.py

@@ -12,12 +12,12 @@ USERAGENT = 'vdirsyncer'
 
 def prepare_auth(auth, username, password):
     if username and password:
-        if auth == 'basic':
+        if auth == 'basic' or auth is None:
             return (username, password)
         elif auth == 'digest':
             from requests.auth import HTTPDigestAuth
             return HTTPDigestAuth(username, password)
-        elif auth == 'guess' or auth is None:
+        elif auth == 'guess':
             try:
                 from requests_toolbelt.auth.guess import GuessAuth
             except ImportError:
@@ -80,9 +80,11 @@ HTTP_STORAGE_PARAMETERS = '''
     :param verify_fingerprint: Optional. SHA1 or MD5 fingerprint of the
         expected server certificate. See :ref:`ssl-tutorial` for more
         information.
-    :param auth: Optional. Either ``basic``, ``digest`` or ``guess``. Default
+    :param auth: Optional. Either ``basic``, ``digest`` or ``guess``. The
-        ``guess``. If you know yours, consider setting it explicitly for
+        default is preemptive Basic auth, sending credentials even if server
-        performance.
+        didn't request them. This saves from an additional roundtrip per
+        request. Consider setting ``guess`` if this causes issues with your
+        server.
     :param auth_cert: Optional. Either a path to a certificate with a client
         certificate and the key or a list of paths to the files with them.
     :param useragent: Default ``vdirsyncer``.