jbeder / yaml-cpp

A YAML parser and emitter in C++
MIT License
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YAML Emitter using YAML::DoubleQuoted when emitted in a destructor of a staticly created struct/class #1281

Open Krausler opened 1 month ago

Krausler commented 1 month ago

What steps will reproduce the problem?

  1. Create a struct/class containing a destructor and a function to serialize an arbitrary type of data, with the destructor calling the serialization function.

  2. Create a static instance of that class and call the serilization function at least once.

What is the expected output? What do you see instead? The expected output would be to see the serialized data, as many times as requested, beeing exactly the same, however, the last time the yaml string is printed, all keys, as well as all strings, are wrapped in double quotes.

Example

struct EmitterTest
{
    ~EmitterTest()
    {
        Serialize();
    }

    void Serialize()
    {
        YAML::Emitter out;

        out << YAML::BeginMap << YAML::Key << "Test";
        out << YAML::BeginMap;
        out << YAML::Key << "String1" << YAML::Value << "String1";
        out << YAML::Key << "String2" << YAML::Value << "String2";
        out << YAML::Key << "String3" << YAML::Value << "Foo";
        out << YAML::EndMap;
        out << YAML::EndMap;

        std::cout << out.c_str() << std::endl;
    }
}

static EmitterTest s_Test;

int main()
{
    s_Test.Serialize();
}

Expected output:

Test:
  String1: String1
  String2: String2
  String3: Foo
Test:
  String1: String1
  String2: String2
  String3: Foo

Actual output:

Test:
  String1: String1
  String2: String2
  String3: Foo
"Test":
  "String1": "String1"
  "String2": "String2"
  "String3": "Foo"

yaml-cpp version: 0.8.0

Additional Information Note that this only happens when Serialize() is called once before destruction. Digging into the problem makes the problem pretty obvious: In emitter.h the function YAML::Emitter::Write(const std::string&) queries the StringFormat::value, by trying to match the string with a regex. This regex match returns false in the serialization called in the destructor, otherwise it returns true.