msvc compile broken by new varint encoding checks #12732

The commit for #9573 has broken the ability to compile libbitcoin_server and the test and bench programs.

The compiler error is:

Error C2338 Signed type required with mode NONNEGATIVE_SIGNED. libbitcoin_server f:\dev\github\bitcoin-msvc\src\serialize.h 316

It looks like the static_assert in serialize.h is now more aggressively checking inputs. I've tracked down one of the static_assert triggers to a change from the same commit in blockchain.cpp line 838:

ss << VARINT(outputs.begin()->second.nHeight * 2 + outputs.begin()->second.fCoinBase, VarIntMode::NONNEGATIVE_SIGNED);

Changing the VarIntMode to DEFAULT removes one of the errors. From my inspection the two fields being encoded are both uint's so shouldn't need the NONNEGATIVE_SIGNED mode (of course that may be different with non-msvc compilers):

outputs.begin()->second.nHeight is uint32_t outputs.begin()->second.fCoinBase is unsigned int

I'm not really sure what the best approach to fix this is but am happy to do any further investigation if required.

Can you try #12737 which removes the use of NONNEGATIVE_SIGNED here?

It seems fCoinBase is treated like a signed value on linux but an unsigned value on windows. #12737 makes it unsigned in all cases.

Should be fixed by #12737.