Merge bitcoin/bitcoin#22156: Allow tr() import only when Taproot is active

fbf485c9b2bf1d056bfea77345a15cf56a9cd786 Allow tr() import only when Taproot is active (Andrew Chow)

Pull request description:

  To avoid issues around fund loss, only allow descriptor wallets to import `tr()` descriptors after taproot has activated.

ACKs for top commit:
  sipa:
    utACK fbf485c9b2bf1d056bfea77345a15cf56a9cd786
  fjahr:
    Code review ACK fbf485c9b2bf1d056bfea77345a15cf56a9cd786
  laanwj:
    Code review ACK fbf485c9b2bf1d056bfea77345a15cf56a9cd786
  prayank23:
    utACK https://github.com/bitcoin/bitcoin/pull/22156/commits/fbf485c9b2bf1d056bfea77345a15cf56a9cd786

Tree-SHA512: 83c43376515eea523dbc89bc5a0fde53e54aec492e49a40c2a33d80fc94aac459e232ae07b024b4bd75b58078c8d090bc7a2d69541c5d3d4834d2f4cfc9c8208

3 files changed, 21 insertions, 0 deletions

diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index 3395741b1b..7cac435e96 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -277,6 +277,9 @@ public:
     //! to be prepared to handle this by ignoring notifications about unknown
     //! removed transactions and already added new transactions.
     virtual void requestMempoolTransactions(Notifications& notifications) = 0;
+
+    //! Check if Taproot has activated
+    virtual bool isTaprootActive() const = 0;
 };
 
 //! Interface to let node manage chain clients (wallets, or maybe tools for
diff --git a/src/node/interfaces.cpp b/src/node/interfaces.cpp
index 58889ee08b..2d05f9d5fb 100644
--- a/src/node/interfaces.cpp
+++ b/src/node/interfaces.cpp
@@ -679,6 +679,12 @@ public:
             notifications.transactionAddedToMempool(entry.GetSharedTx(), 0 /* mempool_sequence */);
         }
     }
+    bool isTaprootActive() const override
+    {
+        LOCK(::cs_main);
+        const CBlockIndex* tip = Assert(m_node.chainman)->ActiveChain().Tip();
+        return VersionBitsState(tip, Params().GetConsensus(), Consensus::DEPLOYMENT_TAPROOT, versionbitscache) == ThresholdState::ACTIVE;
+    }
     NodeContext& m_node;
 };
 } // namespace
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 726b13beac..4e9ba83ead 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -1530,6 +1530,18 @@ static UniValue ProcessDescriptorImport(CWallet& wallet, const UniValue& data, c
             }
         }
 
+        // Taproot descriptors cannot be imported if Taproot is not yet active.
+        // Check if this is a Taproot descriptor
+        CTxDestination dest;
+        ExtractDestination(scripts[0], dest);
+        if (std::holds_alternative<WitnessV1Taproot>(dest)) {
+            // Check if Taproot is active
+            if (!wallet.chain().isTaprootActive()) {
+                // Taproot is not active, raise an error
+                throw JSONRPCError(RPC_WALLET_ERROR, "Cannot import tr() descriptor when Taproot is not active");
+            }
+        }
+
         // If private keys are enabled, check some things.
         if (!wallet.IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
            if (keys.keys.empty()) {