Parse from string returns false

[Krati Chordia]

Hi,
I am trying to send a message on wire with the following protobuf structure

message TestMsg {
    string status = 1;
}

I create an instance of TestMsg and set status as empty and serialize it to a string.

TestMsg m1;
m1.set_status("");

std::string str = m1.SerializeAsString();

Post serialization, str is sent over wire and tried to be parsed. ParseFromString returns false whereas it should not. For any other value, it parses successfully.

TestMsg m2;
m2.ParseFromString(str);  <----- this returns false

Also, if I try to retrieve the value of m2.status(), it will return an empty string even though the parsing returns false.

[Deanna Garcia]

In protobuf, we can't store null strings so to denote a string that isn't set we use the empty string. For this reason, the parsing is returning false to tell you that there isn't a field there but as you're seeing will still parse as an empty string.

[Krati Chordia]

Hi Deanna!
Agreed to your point. But if there is an integer and it's value is set to 0, even then the parsing returns false. Which should not happen.

[Deanna Garcia]

It's the same situation with integers. If we made this return true then if you did not set the value and attempted to serialize it it would return true. I agree that this behavior isn't optimal, we just don't have a great way around it.

[Krati Chordia]

Thanks much for your input. 

-Krati