channels: use Icon.icon_hash

- images: handle generic_get with null icon
 - images: update group dms on delete icon

litecord/blueprints/channels.py

@@ -422,7 +422,7 @@ async def _update_group_dm(channel_id: int, j: dict):
         UPDATE group_dm_channels
         SET icon = $1
         WHERE id = $2
-        """, new_icon, channel_id)
+        """, new_icon.icon_hash, channel_id)
 
 
 @bp.route('/<int:channel_id>', methods=['PUT', 'PATCH'])

litecord/images.py

@@ -274,6 +274,9 @@ class IconManager:
 
     async def generic_get(self, scope, key, icon_hash, **kwargs) -> Icon:
         """Get any icon."""
+        if icon_hash is None:
+            return None
+
         log.debug('GET {} {} {}', scope, key, icon_hash)
         key = str(key)
 
@@ -406,6 +409,12 @@ class IconManager:
         WHERE icon = $1
         """, icon.icon_hash)
 
+        await self.storage.db.execute("""
+        UPDATE group_dm_channels
+        SET icon = NULL
+        WHERE icon = $1
+        """, icon.icon_hash)
+
         await self.storage.db.execute("""
         DELETE FROM icons
         WHERE hash = $1