Interfaces are released twice after commit(), rollback(), close(), free() and detach() #70

handle->commit(&statusWrapper);
handle.reset();

#include <firebird/Interface.h>
#include <fb-cpp/fb-cpp.h>

#include <iostream>
#include <string>

using namespace Firebird;

extern "C" IMaster* ISC_EXPORT fb_get_master_interface();

// Holds two extra references around a call; released() tells how many
// references the call gave back. Expected: 1.
class Probe
{
public:
    explicit Probe(IReferenceCounted* p)
        : ptr(p)
    {
        ptr->addRef();
        before = ptr->release();
        ptr->addRef();
        ptr->addRef();
    }

    int released()
    {
        const int after = ptr->release();
        if (after > 0)
            ptr->release();
        return before + 1 - after;
    }

private:
    IReferenceCounted* ptr;
    int before = 0;
};

int main(int argc, char** argv)
{
    const std::string database = argc > 1 ? argv[1] : "localhost:/tmp/fbcpp-release.fdb";
    fbcpp::Client client{ fb_get_master_interface() };
    fbcpp::Attachment attachment{ client, database, fbcpp::AttachmentOptions()
        .setUserName("SYSDBA").setPassword("masterkey").setCreateDatabase(true) };
    {
        fbcpp::Transaction transaction{ attachment };
        IReferenceCounted* handle = transaction.getHandle().get();
        Probe probe(handle);
        transaction.commit();
        std::cout << "Transaction::commit(): " << probe.released() << " releases\n";
    }
    {
        fbcpp::Transaction transaction{ attachment };
        fbcpp::Statement statement{ attachment, transaction, "select 1 from rdb$database" };
        statement.execute(transaction);
        // the handles first: getHandle() returns a temporary reference
        IReferenceCounted* resultSetHandle = statement.getResultSetHandle().get();
        IReferenceCounted* statementHandle = statement.getStatementHandle().get();
        Probe resultSet(resultSetHandle);
        Probe stmt(statementHandle);
        statement.free();
        std::cout << "Statement::free(), IResultSet: " << resultSet.released() << " releases\n";
        std::cout << "Statement::free(), IStatement: " << stmt.released() << " releases\n";
        IReferenceCounted* transactionHandle = transaction.getHandle().get();
        Probe tra(transactionHandle);
        transaction.rollback();
        std::cout << "Transaction::rollback(): " << tra.released() << " releases\n";
    }
    fbcpp::Attachment second{ client, database, fbcpp::AttachmentOptions()
        .setUserName("SYSDBA").setPassword("masterkey") };
    {
        IReferenceCounted* attachmentHandle = second.getHandle().get();
        Probe probe(attachmentHandle);
        second.disconnect();
        std::cout << "Attachment::disconnect(): " << probe.released() << " releases\n";
    }
    attachment.dropDatabase();
    return 0;
}