Function xdr_cstring_const

src/remote/protocol.cpp:1361–1376

CVC: This function is a little stub to validate that indeed, bpb's aren't overwritten by accident. Even though xdr_string writes to cstr_address, an action we wanted to block, it first allocates a new buffer. The problem is that bpb's aren't copied, but referenced by address, so we don't want a const param being hijacked and its memory location overwritten. The same test has been applied to put_se

// places of the code, so only P_BLOB was changed to use CSTRING_CONST.
// The same function is being used to check P_SGMT & P_DDL.
static inline bool_t xdr_cstring_const(RemoteXdr* xdrs, CSTRING_CONST* cstring)
{
	if (xdr_is_client(xdrs) && xdrs->x_op == XDR_DECODE)
	{
		fb_assert(!(cstring->cstr_length <= cstring->cstr_allocated && cstring->cstr_allocated));

		if (!cstring->cstr_allocated)
		{
			// Normally we should not decode into such CSTRING_CONST at client side
			// May be op, normally never sent to client, was received
			cstring->cstr_address = nullptr;
			cstring->cstr_length = 0;
		}
	}
	return xdr_cstring(xdrs, reinterpret_cast<CSTRING*>(cstring));
}

static inline bool_t xdr_response(RemoteXdr* xdrs, CSTRING* cstring)
{