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https://issues.apache.org/jira/browse/THRIFT-4588?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Joel Croteau closed THRIFT-4588.
--------------------------------
Resolution: Duplicate
Fix Version/s: 0.12.0
Never mind, I see this was already fixed in THRIFT-4531
> local variable referenced before assignment in immutable python structs
> -----------------------------------------------------------------------
>
> Key: THRIFT-4588
> URL: https://issues.apache.org/jira/browse/THRIFT-4588
> Project: Thrift
> Issue Type: Bug
> Components: Python - Compiler
> Affects Versions: 0.11.0
> Reporter: Joel Croteau
> Priority: Major
> Fix For: 0.12.0
>
>
> If an immutable struct has unset optional fields, the Python code generated
> for it will produce an UnboundLocalError when deserializing it. Consider this
> struct:
> {code:java}
> struct TestStruct {
> 1: optional i32 value;
> } (python.immutable="",)
> {code}
> Compiling this to Python with Thrift 0.11.0, the ttypes.py has this read
> method:
> {code:java}
> @classmethod
> def read(cls, iprot):
> if iprot._fast_decode is not None and isinstance(iprot.trans,
> TTransport.CReadableTransport) and cls.thrift_spec is not None:
> return iprot._fast_decode(None, iprot, [cls, cls.thrift_spec])
> iprot.readStructBegin()
> while True:
> (fname, ftype, fid) = iprot.readFieldBegin()
> if ftype == TType.STOP:
> break
> if fid == 1:
> if ftype == TType.I32:
> value = iprot.readI32()
> else:
> iprot.skip(ftype)
> else:
> iprot.skip(ftype)
> iprot.readFieldEnd()
> iprot.readStructEnd()
> return cls(
> value=value,
> )
> {code}
> Since no default is ever set for value, if it is never set while reading the
> input file, it will attempt to use an unbound variable when creating the
> class at the end of this method. For a non-immutable struct, the analogous
> code is:
> {code:java}
> def __init__(self, value=None,):
> self.value = value
> def read(self, iprot):
> if iprot._fast_decode is not None and isinstance(iprot.trans,
> TTransport.CReadableTransport) and self.thrift_spec is not None:
> iprot._fast_decode(self, iprot, [self.__class__,
> self.thrift_spec])
> return
> iprot.readStructBegin()
> while True:
> (fname, ftype, fid) = iprot.readFieldBegin()
> if ftype == TType.STOP:
> break
> if fid == 1:
> if ftype == TType.I32:
> self.value = iprot.readI32()
> else:
> iprot.skip(ftype)
> else:
> iprot.skip(ftype)
> iprot.readFieldEnd()
> iprot.readStructEnd()
> {code}
> which works in this case because value is given a default value of None. It
> would probably make sense to set value to None at the start of this method.
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