Closes#3182 - Least Authority Issue D
Prevent undefined behaviour when null pointer is passed in as parameter to function
Includes a backport of bitcoin/bitcoin#10250.
Details of Sapling datatypes will be filled in later; for now, they are treated
as binary blobs.
Includes code cherry-picked from upstream commit:
7030d9eb47254499bba14f1c00abc6bf493efd91
BIP144: Serialization, hashes, relay (sender side)
Remove the nType and nVersion as parameters to all serialization methods
and functions. There is only one place where it's read and has an impact
(in CAddress), and even there it does not impact any of the recursively
invoked serializers.
Instead, the few places that need nType or nVersion are changed to read
it directly from the stream object, through GetType() and GetVersion()
methods which are added to all stream classes.
Given that in default GetSerializeSize implementations created by
ADD_SERIALIZE_METHODS we're already using CSizeComputer(), get rid
of the specialized GetSerializeSize methods everywhere, and just use
CSizeComputer. This removes a lot of code which isn't actually used
anywhere.
For CCompactSize and CVarInt this actually removes a more efficient
size computing algorithm, which is brought back in a later commit.
The stream implementations had two cascading layers (the upper one
with operator<< and operator>>, and a lower one with read and write).
The lower layer's functions are never cascaded (nor should they, as
they should only be used from the higher layer), so make them return
void instead.
This makes it easier for us to replace it if desired, since it's now only in
one spot. Also, it avoids the openssl include from allocators.h, which
essentially forced openssl to be included from every compilation unit.
