saml: do not configure choice for attribute names at the model level as it breaks model validation before running migrations

authentic2/saml/admin.py

@@ -23,6 +23,9 @@ from authentic2.saml.models import LibertySession
 from authentic2.saml.models import SAMLAttribute
 from authentic2.http_utils import get_url
 
+from authentic2.decorators import to_iter
+from authentic2.attributes_ng.engine import get_attribute_names
+
 from . import admin_views
 
 logger = logging.getLogger(__name__)
@@ -165,6 +168,11 @@ def update_metadata(modeladmin, request, queryset):
 class SAMLAttributeInlineAdmin(GenericTabularInline):
     model = SAMLAttribute
 
+    def formfield_for_choice_field(self, db_field, request, **kwargs):
+        if db_field.name == 'attribute_name':
+            kwargs['choices'] = to_iter(get_attribute_names)({'user': None, 'request': None})
+        return super(SAMLAttributeInlineAdmin, self).formfield_for_choice_field(db_field, request, **kwargs)
+
 
 class LibertyProviderAdmin(admin.ModelAdmin):
     form = LibertyProviderForm

authentic2/saml/models.py

@@ -24,8 +24,6 @@ except ImportError:
 from fields import PickledObjectField, MultiSelectField
 
 from . import app_settings, managers
-from ..decorators import to_iter
-from ..attributes_ng.engine import get_attribute_names
 from .. import managers as a2_managers
 
 def metadata_validator(meta):
@@ -348,7 +346,7 @@ class SAMLAttribute(models.Model):
             blank=True)
     attribute_name = models.CharField(max_length=64,
             verbose_name=_('attribute name'),
-            choices=to_iter(get_attribute_names)({'user': None, 'request': None}))
+            choices=(('', 'None'),))
 
     def clean(self):
         super(SAMLAttribute, self).clean()