GCC 12.2.0 build warning for uninitialized variable

Describe the bug
The GCC 12.2.0 compiler warns that a variable may be uninitialized when building JSONCPP, specifically here (v):

  case tokenNull:
    {
    Value v;
    currentValue().swapPayload(v);
    currentValue().setOffsetStart(token.start_ - begin_);
    currentValue().setOffsetLimit(token.end_ - begin_);
    }
    break;

in jsoncpp.cpp

To Reproduce
Just building jsoncpp.cpp in a project.

Expected behavior
No warning.

I even expect that :

Value v(); 

We resolve the issue.

Desktop (please complete the following information):

• vanilla Arch Linux, GCC 12.2.0

Start with the tokenNull case and the Value v declaration in jsoncpp.cpp. Reproduce the build with GCC 12.2.0 on the reported Arch Linux setup, then verify the warning is eliminated without changing the intended behavior. Done means jsoncpp.cpp builds without the uninitialized-variable warning.