8276e70de Adding assert to avoid a memory access violation inside of PartialMerkleTree::CalcHash() (Chris Stewart)
Pull request description:
Fixing a possible memory access violation in CPartialMerkleTree::CalcHash().
This can happen if we some how a merkle tree with zero txids. I don't think this can happen in practice as we only send merkle block messages on the p2p network as of now -- we cannot receive them.
This was found with #8469, specifically using this [generator](https://github.com/Christewart/bitcoin/blob/rapidcheck/src/test/gen/merkleblock_gen.h#L52-L77) which will cause a memory access violation on [this test case](https://github.com/Christewart/bitcoin/blob/rapidcheck/src/test/merkleblock_properties.cpp#L48).
Tree-SHA512: b95904ec45ea3f082c7722161d93ee06b24c706fbffa909a6e995ed14788aed2830f91b626da6f0347660c45874a0735dab61c9440b59c949c690af4165c83fb
dd07068 Fixed typo in documentation for merkleblock.h (Mikerah)
Tree-SHA512: 92655c8022eb33852c116da517b12bd17b3b668713cd85fe185a15245ea9810605626b1d0955fa117f7b56863e0a52b3a86dab42409332452b5eb72a7d34f30d
d59a518 Use fixed preallocation instead of costly GetSerializeSize (Pieter Wuille)
25a211a Add optimized CSizeComputer serializers (Pieter Wuille)
a2929a2 Make CSerAction's ForRead() constexpr (Pieter Wuille)
a603925 Avoid -Wshadow errors (Pieter Wuille)
5284721 Get rid of nType and nVersion (Pieter Wuille)
657e05a Make GetSerializeSize a wrapper on top of CSizeComputer (Pieter Wuille)
fad9b66 Make nType and nVersion private and sometimes const (Pieter Wuille)
c2c5d42 Make streams' read and write return void (Pieter Wuille)
50e8a9c Remove unused ReadVersion and WriteVersion (Pieter Wuille)
