WIP RPC that doesn't quite work yet

src/rpc/blockchain.cpp

@@ -856,6 +856,41 @@ UniValue gettxoutsetinfo(const UniValue& params, bool fHelp, const CPubKey& mypk
     return ret;
 }
 
+UniValue getblockmerkletree(const UniValue& params, bool fHelp, const CPubKey& mypk)
+{
+    if (fHelp || params.size() != 1 )
+        throw runtime_error(
+            "getblockmerkletree height\n"
+            "\nGet full merkletree for a given Hush or HSC block height.\n"
+            "\nArguments:\n"
+            "1. height                      (int, required) block height\n"
+            "\nResult:\n"
+            "\"hex\"      (string) the  merkle tree hex encoded\n"
+            + HelpExampleCli("getblockmerkletree", "290000")
+            + HelpExampleRpc("getblockmerkletree", "290000")
+        );
+
+    CBlockIndex* phushblockindex;
+    uint256 blockRoot;
+    SaplingMerkleTree tree;
+
+    int nHeight = params[0].get_int();
+    if ( (nHeight < 1) || (nHeight > chainActive.LastTip()->GetHeight()) ) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid Hush or HSC block height parameter");
+    }
+
+    phushblockindex = chainActive[nHeight];
+    blockRoot = phushblockindex->pprev->hashFinalSaplingRoot;
+    if( pcoinsTip->GetSaplingAnchorAt(blockRoot, tree) ) {
+        CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
+        ss << tree.path();
+        std::vector<unsigned char> merklepath(ss.begin(), ss.end());
+        //TODO: this returns the same, wrong data for all heights
+        return HexStr(merklepath);
+    } else {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Could not find merkletree");
+    }
+}
 
 UniValue kvsearch(const UniValue& params, bool fHelp, const CPubKey& mypk)
 {
@@ -1877,6 +1912,7 @@ static const CRPCCommand commands[] =
     { "blockchain",         "getblockcount",          &getblockcount,          true  },
     { "blockchain",         "getblock",               &getblock,               true  },
     { "blockchain",         "getblockhash",           &getblockhash,           true  },
+    { "blockchain",         "getblockmerkletree",     &getblockmerkletree,     true  },
     { "blockchain",         "getblockheader",         &getblockheader,         true  },
     { "blockchain",         "getchaintips",           &getchaintips,           true  },
     { "blockchain",         "getchaintxstats",        &getchaintxstats,        true  },

src/rpc/client.cpp

@@ -63,6 +63,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "getbalance", 1 },
     { "getbalance", 2 },
     { "getblockhash", 0 },
+    { "getblockmerkletree", 0 },
     { "move", 2 },
     { "move", 3 },
     { "sendfrom", 2 },

src/zcash/IncrementalMerkleTree.hpp

@@ -108,6 +108,7 @@ public:
     IncrementalWitness<Depth, Hash> witness() const {
         return IncrementalWitness<Depth, Hash>(*this);
     }
+    MerklePath path(std::deque<Hash> filler_hashes = std::deque<Hash>()) const;
 
     ADD_SERIALIZE_METHODS;
 
@@ -135,7 +136,6 @@ private:
 
     // Collapsed "left" subtrees ordered toward the root of the tree.
     std::vector<boost::optional<Hash>> parents;
-    MerklePath path(std::deque<Hash> filler_hashes = std::deque<Hash>()) const;
     Hash root(size_t depth, std::deque<Hash> filler_hashes = std::deque<Hash>()) const;
     bool is_complete(size_t depth = Depth) const;
     size_t next_depth(size_t skip) const;