Add OutputType::BECH32M

Bech32m addresses need their own OutputType

We are not ready to create DescriptorScriptPubKeyMans which produce
bech32m addresses. So don't allow generating them.

Author: achow101

src/outputtype.cpp

@@ -18,6 +18,7 @@
 static const std::string OUTPUT_TYPE_STRING_LEGACY = "legacy";
 static const std::string OUTPUT_TYPE_STRING_P2SH_SEGWIT = "p2sh-segwit";
 static const std::string OUTPUT_TYPE_STRING_BECH32 = "bech32";
+static const std::string OUTPUT_TYPE_STRING_BECH32M = "bech32m";
 
 bool ParseOutputType(const std::string& type, OutputType& output_type)
 {
@@ -30,6 +31,9 @@ bool ParseOutputType(const std::string& type, OutputType& output_type)
     } else if (type == OUTPUT_TYPE_STRING_BECH32) {
         output_type = OutputType::BECH32;
         return true;
+    } else if (type == OUTPUT_TYPE_STRING_BECH32M) {
+        output_type = OutputType::BECH32M;
+        return true;
     }
     return false;
 }
@@ -40,6 +44,7 @@ const std::string& FormatOutputType(OutputType type)
     case OutputType::LEGACY: return OUTPUT_TYPE_STRING_LEGACY;
     case OutputType::P2SH_SEGWIT: return OUTPUT_TYPE_STRING_P2SH_SEGWIT;
     case OutputType::BECH32: return OUTPUT_TYPE_STRING_BECH32;
+    case OutputType::BECH32M: return OUTPUT_TYPE_STRING_BECH32M;
     } // no default case, so the compiler can warn about missing cases
     assert(false);
 }
@@ -59,6 +64,7 @@ CTxDestination GetDestinationForKey(const CPubKey& key, OutputType type)
             return witdest;
         }
     }
+    case OutputType::BECH32M: {} // This function should never be used with BECH32M, so let it assert
     } // no default case, so the compiler can warn about missing cases
     assert(false);
 }
@@ -98,6 +104,7 @@ CTxDestination AddAndGetDestinationForScript(FillableSigningProvider& keystore,
             return ScriptHash(witprog);
         }
     }
+    case OutputType::BECH32M: {} // This function should not be used for BECH32M, so let it assert
     } // no default case, so the compiler can warn about missing cases
     assert(false);
 }

src/outputtype.h

@@ -18,12 +18,14 @@ enum class OutputType {
     LEGACY,
     P2SH_SEGWIT,
     BECH32,
+    BECH32M,
 };
 
 static constexpr auto OUTPUT_TYPES = std::array{
     OutputType::LEGACY,
     OutputType::P2SH_SEGWIT,
     OutputType::BECH32,
+    OutputType::BECH32M,
 };
 
 [[nodiscard]] bool ParseOutputType(const std::string& str, OutputType& output_type);

src/wallet/scriptpubkeyman.cpp

@@ -1889,6 +1889,12 @@ bool DescriptorScriptPubKeyMan::AddDescriptorKeyWithDB(WalletBatch& batch, const
 
 bool DescriptorScriptPubKeyMan::SetupDescriptorGeneration(const CExtKey& master_key, OutputType addr_type)
 {
+    if (addr_type == OutputType::BECH32M) {
+        // Don't allow setting up taproot descriptors yet
+        // TODO: Allow setting up taproot descriptors
+        return false;
+    }
+
     LOCK(cs_desc_man);
     assert(m_storage.IsWalletFlagSet(WALLET_FLAG_DESCRIPTORS));
 
@@ -1918,6 +1924,7 @@ bool DescriptorScriptPubKeyMan::SetupDescriptorGeneration(const CExtKey& master_
         desc_prefix = "wpkh(" + xpub + "/84'";
         break;
     }
+    case OutputType::BECH32M: assert(false); // TODO: Setup taproot descriptor
     } // no default case, so the compiler can warn about missing cases
     assert(!desc_prefix.empty());
 

src/wallet/wallet.cpp

@@ -3086,6 +3086,11 @@ void CWallet::SetupDescriptorScriptPubKeyMans()
 
         for (bool internal : {false, true}) {
             for (OutputType t : OUTPUT_TYPES) {
+                if (t == OutputType::BECH32M) {
+                    // Skip taproot (bech32m) for now
+                    // TODO: Setup taproot (bech32m) descriptors by default
+                    continue;
+                }
                 auto spk_manager = std::unique_ptr<DescriptorScriptPubKeyMan>(new DescriptorScriptPubKeyMan(*this, internal));
                 if (IsCrypted()) {
                     if (IsLocked()) {