Add getCoinbaseMerklePath() to Mining interface

Author: Sjors

src/interfaces/mining.h

@@ -42,6 +42,13 @@ class BlockTemplate
     virtual CTransactionRef getCoinbaseTx() = 0;
     virtual std::vector<unsigned char> getCoinbaseCommitment() = 0;
     virtual int getWitnessCommitmentIndex() = 0;
+
+    /**
+     * Compute merkle path to the coinbase transaction
+     *
+     * @return merkle path ordered from the deepest
+     */
+    virtual std::vector<uint256> getCoinbaseMerklePath() = 0;
 };
 
 //! Interface giving clients (RPC, Stratum v2 Template Provider in the future)

src/ipc/capnp/mining.capnp

@@ -31,6 +31,7 @@ interface BlockTemplate $Proxy.wrap("interfaces::BlockTemplate") {
     getCoinbaseTx @4 (context: Proxy.Context) -> (result: Data);
     getCoinbaseCommitment @5 (context: Proxy.Context) -> (result: Data);
     getWitnessCommitmentIndex @6 (context: Proxy.Context) -> (result: Int32);
+    getCoinbaseMerklePath @7 (context: Proxy.Context) -> (result: List(Data));
 }
 
 struct BlockCreateOptions $Proxy.wrap("node::BlockCreateOptions") {

src/node/interfaces.cpp

@@ -8,6 +8,7 @@
 #include <chain.h>
 #include <chainparams.h>
 #include <common/args.h>
+#include <consensus/merkle.h>
 #include <consensus/validation.h>
 #include <deploymentstatus.h>
 #include <external_signer.h>
@@ -910,6 +911,11 @@ class BlockTemplateImpl : public BlockTemplate
         return GetWitnessCommitmentIndex(m_block_template->block);
     }
 
+    std::vector<uint256> getCoinbaseMerklePath() override
+    {
+        return BlockMerkleBranch(m_block_template->block);
+    }
+
     const std::unique_ptr<CBlockTemplate> m_block_template;
 };