Use GenerateSlugMixin for collections.

Use the new way of generating slugs also for collections.
Also drop the dummy_db arg to check_collection_slug_used.

mediagoblin/db/mixin.py

@@ -242,22 +242,13 @@ class MediaCommentMixin(object):
         return cleaned_markdown_conversion(self.content)
 
 
-class CollectionMixin(object):
-    def generate_slug(self):
+class CollectionMixin(GenerateSlugMixin):
+    def check_slug_used(self, slug):
         # import this here due to a cyclic import issue
         # (db.models -> db.mixin -> db.util -> db.models)
         from mediagoblin.db.util import check_collection_slug_used
 
-        self.slug = slugify(self.title)
-
-        duplicate = check_collection_slug_used(mg_globals.database,
-            self.creator, self.slug, self.id)
-
-        if duplicate:
-            if self.id is not None:
-                self.slug = u"%s-%s" % (self.id, self.slug)
-            else:
-                self.slug = None
+        return check_collection_slug_used(self.creator, slug, self.id)
 
     @property
     def description_html(self):

mediagoblin/db/util.py

@@ -59,7 +59,7 @@ def clean_orphan_tags(commit=True):
         Session.commit()
 
 
-def check_collection_slug_used(dummy_db, creator_id, slug, ignore_c_id):
+def check_collection_slug_used(creator_id, slug, ignore_c_id):
     filt = (Collection.creator == creator_id) \
         & (Collection.slug == slug)
     if ignore_c_id is not None:

mediagoblin/edit/views.py

@@ -308,7 +308,7 @@ def edit_collection(request, collection):
     if request.method == 'POST' and form.validate():
         # Make sure there isn't already a Collection with such a slug
         # and userid.
-        slug_used = check_collection_slug_used(request.db, collection.creator,
+        slug_used = check_collection_slug_used(collection.creator,
                 form.slug.data, collection.id)
 
         # Make sure there isn't already a Collection with this title