Taking the value of the element 0 of a vector when the vector is empty #601

I have compiled bitcoin 0.4 under Visual Studio 2010. I know this isn't supported, but the bug isn't connected to Visual Studio.

In util.h there is this block of code:

inline uint160 Hash160(const std::vector<unsigned char>& vch)
{
    uint256 hash1;
    SHA256(&vch[0], vch.size(), (unsigned char*)&hash1);
    uint160 hash2;
    RIPEMD160((unsigned char*)&hash1, sizeof(hash1), (unsigned char*)&hash2);
    return hash2;
}

Now the problem is that if there isn't a wallet the function is called with an empty vch. In "debug" mode the &vch[0] asserts, because 0 is >= the size of the vector. Read for example http://stackoverflow.com/questions/2728255/c-getting-the-address-of-the-start-of-an-stdvector

MSVC is wrong here, taking the address of an empty vector should be legal. That stack overflow page also gives the workaround: add #define _SECURE_SCL 0, or even better, define it in your build script.

Although we accept MSVC compatibility patches, we won't actively ourselves make changes to make MSVC happy. Closing.