3 files changed, 27 insertions, 17 deletions
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index c05233d0af..1994b2090a 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -306,7 +306,7 @@ static UniValue getrawchangeaddress(const JSONRPCRequest& request)
         throw JSONRPCError(RPC_WALLET_ERROR, "Error: This wallet has no available keys");
     }
 
-    OutputType output_type = pwallet->m_default_change_type != OutputType::CHANGE_AUTO ? pwallet->m_default_change_type : pwallet->m_default_address_type;
+    OutputType output_type = pwallet->m_default_change_type.get_value_or(pwallet->m_default_address_type);
     if (!request.params[0].isNull()) {
         if (!ParseOutputType(request.params[0].get_str(), output_type)) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Unknown address type '%s'", request.params[0].get_str()));
@@ -2993,10 +2993,11 @@ void FundTransaction(CWallet* const pwallet, CMutableTransaction& tx, CAmount& f
             if (options.exists("changeAddress")) {
                 throw JSONRPCError(RPC_INVALID_PARAMETER, "Cannot specify both changeAddress and address_type options");
             }
-            coinControl.m_change_type = pwallet->m_default_change_type;
-            if (!ParseOutputType(options["change_type"].get_str(), *coinControl.m_change_type)) {
+            OutputType out_type;
+            if (!ParseOutputType(options["change_type"].get_str(), out_type)) {
                 throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Unknown change type '%s'", options["change_type"].get_str()));
             }
+            coinControl.m_change_type.emplace(out_type);
         }
 
         coinControl.fAllowWatchOnly = ParseIncludeWatchonly(options["includeWatching"], *pwallet);
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 57eec9baf9..3fd66c1410 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2653,11 +2653,11 @@ static uint32_t GetLocktimeForNewTransaction(interfaces::Chain& chain, const uin
     return locktime;
 }
 
-OutputType CWallet::TransactionChangeType(OutputType change_type, const std::vector<CRecipient>& vecSend)
+OutputType CWallet::TransactionChangeType(const Optional<OutputType>& change_type, const std::vector<CRecipient>& vecSend)
 {
     // If -changetype is specified, always use that change type.
-    if (change_type != OutputType::CHANGE_AUTO) {
-        return change_type;
+    if (change_type) {
+        return *change_type;
     }
 
     // if m_default_address_type is legacy, use legacy address as change (even
@@ -3826,14 +3826,20 @@ std::shared_ptr<CWallet> CWallet::CreateWalletFromFile(interfaces::Chain& chain,
         }
     }
 
-    if (!gArgs.GetArg("-addresstype", "").empty() && !ParseOutputType(gArgs.GetArg("-addresstype", ""), walletInstance->m_default_address_type)) {
-        error = strprintf(_("Unknown address type '%s'"), gArgs.GetArg("-addresstype", ""));
-        return nullptr;
+    if (!gArgs.GetArg("-addresstype", "").empty()) {
+        if (!ParseOutputType(gArgs.GetArg("-addresstype", ""), walletInstance->m_default_address_type)) {
+            error = strprintf(_("Unknown address type '%s'"), gArgs.GetArg("-addresstype", ""));
+            return nullptr;
+        }
     }
 
-    if (!gArgs.GetArg("-changetype", "").empty() && !ParseOutputType(gArgs.GetArg("-changetype", ""), walletInstance->m_default_change_type)) {
-        error = strprintf(_("Unknown change type '%s'"), gArgs.GetArg("-changetype", ""));
-        return nullptr;
+    if (!gArgs.GetArg("-changetype", "").empty()) {
+        OutputType out_type;
+        if (!ParseOutputType(gArgs.GetArg("-changetype", ""), out_type)) {
+            error = strprintf(_("Unknown change type '%s'"), gArgs.GetArg("-changetype", ""));
+            return nullptr;
+        }
+        walletInstance->m_default_change_type = out_type;
     }
 
     if (gArgs.IsArgSet("-mintxfee")) {
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 9931671fb4..e7b480af97 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -105,9 +105,6 @@ class ReserveDestination;
 //! Default for -addresstype
 constexpr OutputType DEFAULT_ADDRESS_TYPE{OutputType::BECH32};
 
-//! Default for -changetype
-constexpr OutputType DEFAULT_CHANGE_TYPE{OutputType::CHANGE_AUTO};
-
 static constexpr uint64_t KNOWN_WALLET_FLAGS =
         WALLET_FLAG_AVOID_REUSE
     |   WALLET_FLAG_BLANK_WALLET
@@ -934,7 +931,7 @@ public:
     Balance GetBalance(int min_depth = 0, bool avoid_reuse = true) const;
     CAmount GetAvailableBalance(const CCoinControl* coinControl = nullptr) const;
 
-    OutputType TransactionChangeType(OutputType change_type, const std::vector<CRecipient>& vecSend);
+    OutputType TransactionChangeType(const Optional<OutputType>& change_type, const std::vector<CRecipient>& vecSend);
 
     /**
      * Insert additional inputs into the transaction by
@@ -1012,7 +1009,13 @@ public:
     CFeeRate m_fallback_fee{DEFAULT_FALLBACK_FEE};
     CFeeRate m_discard_rate{DEFAULT_DISCARD_FEE};
     OutputType m_default_address_type{DEFAULT_ADDRESS_TYPE};
-    OutputType m_default_change_type{DEFAULT_CHANGE_TYPE};
+    /**
+     * Default output type for change outputs. When unset, automatically choose type
+     * based on address type setting and the types other of non-change outputs
+     * (see -changetype option documentation and implementation in
+     * CWallet::TransactionChangeType for details).
+     */
+    Optional<OutputType> m_default_change_type{};
     /** Absolute maximum transaction fee (in satoshis) used by default for the wallet */
     CAmount m_default_max_tx_fee{DEFAULT_TRANSACTION_MAXFEE};