diff options
Diffstat (limited to 'lib/sqlalchemy/sql/elements.py')
| -rw-r--r-- | lib/sqlalchemy/sql/elements.py | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/lib/sqlalchemy/sql/elements.py b/lib/sqlalchemy/sql/elements.py index 625e1d94b..eae06377f 100644 --- a/lib/sqlalchemy/sql/elements.py +++ b/lib/sqlalchemy/sql/elements.py @@ -390,7 +390,14 @@ class ClauseElement( skip = self._memoized_keys c = self.__class__.__new__(self.__class__) - c.__dict__ = {k: v for k, v in self.__dict__.items() if k not in skip} + + if skip: + # ensure this iteration remains atomic + c.__dict__ = { + k: v for k, v in self.__dict__.copy().items() if k not in skip + } + else: + c.__dict__ = self.__dict__.copy() # this is a marker that helps to "equate" clauses to each other # when a Select returns its list of FROM clauses. the cloning |