[Bugfix] 修复AssetUserManager.get获取username为""的AuthBook对象时，返回多个结果的bug

apps/assets/backends/external/db.py

@@ -11,7 +11,7 @@ class AuthBookBackend(BaseBackend):
     @classmethod
     def filter(cls, username=None, asset=None, latest=True):
         queryset = AuthBook.objects.all()
-        if username:
+        if username is not None:
             queryset = queryset.filter(username=username)
         if asset:
             queryset = queryset.filter(asset=asset)

apps/assets/backends/internal/admin_user.py

@@ -27,7 +27,7 @@ class AdminUserBackend(BaseBackend):
         instances = []
         assets = cls._get_assets(asset)
         for asset in assets:
-            if username and asset.admin_user.username != username:
+            if username is not None and asset.admin_user.username != username:
                 continue
             instance = construct_authbook_object(asset.admin_user, asset)
             instances.append(instance)

apps/assets/backends/internal/system_user.py

@@ -30,7 +30,7 @@ class SystemUserBackend(BaseBackend):
     @classmethod
     def _filter_system_users_by_username(cls, system_users, username):
         _system_users = cls._distinct_system_users_by_username(system_users)
-        if username:
+        if username is not None:
             _system_users = [su for su in _system_users if username == su.username]
         return _system_users