ldap-auth: fixed wrong Missing check

rhodecode/authentication/plugins/auth_ldap.py

@@ -46,8 +46,9 b' log = logging.getLogger(__name__)'
 try:
     import ldap
 except ImportError:
-    # means that python-ldap is not installed
-    ldap = Missing()
+    # means that python-ldap is not installed, we use Missing object to mark
+    # ldap lib is Missing
+    ldap = Missing
 
 
 def plugin_factory(plugin_id, *args, **kwds):
@@ -182,7 +183,7 b' class AuthLdap(object):'
                  tls_kind='PLAIN', tls_reqcert='DEMAND', ldap_version=3,
                  search_scope='SUBTREE', attr_login='uid',
                  ldap_filter='(&(objectClass=user)(!(objectClass=computer)))'):
-        if isinstance(ldap, Missing):
+        if ldap == Missing:
             raise LdapImportError("Missing or incompatible ldap library")
 
         self.ldap_version = ldap_version

rhodecode/tests/lib/auth_modules/test_auth_modules.py

@@ -155,3 +155,29 b' class TestRhodeCodeAuthPlugin(object):'
         self.password_generator_mock = password_generator_patch.start()
         self.password_generator_mock.return_value = 'new-password'
         self.finalizers.append(password_generator_patch.stop)
+
+
+def test_missing_ldap():
+    from rhodecode.model.validators import Missing
+
+    try:
+        import ldap_not_existing
+    except ImportError:
+        # means that python-ldap is not installed
+        ldap_not_existing = Missing
+
+    # missing is singleton
+    assert ldap_not_existing == Missing
+
+
+def test_import_ldap():
+    from rhodecode.model.validators import Missing
+
+    try:
+        import ldap
+    except ImportError:
+        # means that python-ldap is not installed
+        ldap = Missing
+
+    # missing is singleton
+    assert False is (ldap == Missing)