BIP152: Test net msg ser/der and diff encoding

This adds tests for serialization of BIP152 network messages and
tests specifically for the differential encoding of the transaction
indicies of 'getblocktx'. Previously, this code contained an
off-by-one error.

src/network/message.rs

@@ -453,6 +453,8 @@ mod test {
     use crate::blockdata::script::Script;
     use crate::network::message_bloom::{FilterAdd, FilterLoad, BloomFlags};
     use crate::MerkleBlock;
+    use crate::network::message_compact_blocks::{GetBlockTxn, SendCmpct};
+    use crate::util::bip152::BlockTransactionsRequest;
 
     fn hash(slice: [u8;32]) -> Hash {
         Hash::from_slice(&slice).unwrap()
@@ -467,6 +469,9 @@ mod test {
         let header: BlockHeader = deserialize(&Vec::from_hex("010000004ddccd549d28f385ab457e98d1b11ce80bfea2c5ab93015ade4973e400000000bf4473e53794beae34e64fccc471dace6ae544180816f89591894e0f417a914cd74d6e49ffff001d323b3a7b").unwrap()).unwrap();
         let script: Script = deserialize(&Vec::from_hex("1976a91431a420903c05a0a7de2de40c9f02ebedbacdc17288ac").unwrap()).unwrap();
         let merkle_block: MerkleBlock = deserialize(&Vec::from_hex("0100000079cda856b143d9db2c1caff01d1aecc8630d30625d10e8b4b8b0000000000000b50cc069d6a3e33e3ff84a5c41d9d3febe7c770fdcc96b2c3ff60abe184f196367291b4d4c86041b8fa45d630100000001b50cc069d6a3e33e3ff84a5c41d9d3febe7c770fdcc96b2c3ff60abe184f19630101").unwrap()).unwrap();
+        let cmptblock = deserialize(&Vec::from_hex("00000030d923ad36ff2d955abab07f8a0a6e813bc6e066b973e780c5e36674cad5d1cd1f6e265f2a17a0d35cbe701fe9d06e2c6324cfe135f6233e8b767bfa3fb4479b71115dc562ffff7f2006000000000000000000000000010002000000010000000000000000000000000000000000000000000000000000000000000000ffffffff0302ee00ffffffff0100f9029500000000015100000000").unwrap()).unwrap();
+        let blocktxn = deserialize(&Vec::from_hex("2e93c0cff39ff605020072d96bc3a8d20b8447e294d08092351c8583e08d9b5a01020000000001010000000000000000000000000000000000000000000000000000000000000000ffffffff0402dc0000ffffffff0200f90295000000001976a9142b4569203694fc997e13f2c0a1383b9e16c77a0d88ac0000000000000000266a24aa21a9ede2f61c3f71d1defd3fa999dfa36953755c690689799962b48bebd836974e8cf90120000000000000000000000000000000000000000000000000000000000000000000000000").unwrap()).unwrap();
+
 
         let msgs = vec![
             NetworkMessage::Version(version_msg),
@@ -502,6 +507,10 @@ mod test {
             NetworkMessage::WtxidRelay,
             NetworkMessage::AddrV2(vec![AddrV2Message{ addr: AddrV2::Ipv4(Ipv4Addr::new(127, 0, 0, 1)), port: 0, services: ServiceFlags::NONE, time: 0 }]),
             NetworkMessage::SendAddrV2,
+            NetworkMessage::CmpctBlock(cmptblock),
+            NetworkMessage::GetBlockTxn(GetBlockTxn { txs_request: BlockTransactionsRequest { block_hash: hash([11u8; 32]).into(), indexes: vec![0, 1, 2, 3, 10, 3002] } }),
+            NetworkMessage::BlockTxn(blocktxn),
+            NetworkMessage::SendCmpct(SendCmpct{send_compact: true, version: 8333}),
         ];
 
         for msg in msgs {

src/util/bip152.rs

@@ -362,8 +362,8 @@ impl BlockTransactions {
 #[cfg(test)]
 mod test {
     use super::*;
+    use crate::consensus::encode::{deserialize, serialize};
     use crate::hashes::hex::FromHex;
-    use crate::consensus::encode::deserialize;
     use crate::{
         Block, BlockHash, BlockHeader, OutPoint, Script, Sequence, Transaction, TxIn, TxMerkleNode,
         TxOut, Txid, Witness,
@@ -430,4 +430,56 @@ mod test {
 
         assert_eq!(compact, compact_expected);
     }
+
+    #[test]
+    fn test_getblocktx_differential_encoding_de_and_serialization() {
+        let testcases = vec![
+            // differentially encoded VarInts, indicies
+            (vec![4, 0, 5, 1, 10], vec![0, 6, 8, 19]),
+            (vec![1, 0], vec![0]),
+            (vec![5, 0, 0, 0, 0, 0], vec![0, 1, 2, 3, 4]),
+            (vec![3, 1, 1, 1], vec![1, 3, 5]),
+            (vec![3, 0, 0, 253, 0, 1], vec![0, 1, 258]), // .., 253, 0, 1] == VarInt(256)
+        ];
+        let deser_errorcases = vec![
+            vec![2, 255, 254, 255, 255, 255, 255, 255, 255, 255, 0], // .., 255, 254, .., 255] == VarInt(u64::MAX-1)
+            vec![1, 255, 255, 255, 255, 255, 255, 255, 255, 255], // .., 255, 255, .., 255] == VarInt(u64::MAX)
+        ];
+        for testcase in testcases {
+            {
+                // test deserialization
+                let mut raw: Vec<u8> = [0u8; 32].to_vec();
+                raw.extend(testcase.0.clone());
+                let btr: BlockTransactionsRequest = deserialize(&raw.to_vec()).unwrap();
+                assert_eq!(testcase.1, btr.indexes);
+            }
+            {
+                // test serialization
+                let raw: Vec<u8> = serialize(&BlockTransactionsRequest {
+                    block_hash: Hash::all_zeros(),
+                    indexes: testcase.1,
+                });
+                let mut expected_raw: Vec<u8> = [0u8; 32].to_vec();
+                expected_raw.extend(testcase.0);
+                assert_eq!(expected_raw, raw);
+            }
+        }
+        for errorcase in deser_errorcases {
+            {
+                // test that we return Err() if deserialization fails (and don't panic)
+                let mut raw: Vec<u8> = [0u8; 32].to_vec();
+                raw.extend(errorcase);
+                assert!(deserialize::<BlockTransactionsRequest>(&raw.to_vec()).is_err());
+            }
+        }
+    }
+
+    #[test]
+    #[should_panic] // 'attempt to add with overflow' in consensus_encode()
+    fn test_getblocktx_panic_when_encoding_u64_max() {
+        serialize(&BlockTransactionsRequest {
+            block_hash: Hash::all_zeros(),
+            indexes: vec![core::u64::MAX],
+        });
+    }
 }