[wallet] use P2WPKH change output if any destination is P2WPKH or P2WSH

Only if -changetype is not set and -addresstype is not "legacy".

1 files changed, 5 insertions, 3 deletions

diff --git a/src/wallet/init.cpp b/src/wallet/init.cpp
index 0f453f154f..7d61d708a1 100644
--- a/src/wallet/init.cpp
+++ b/src/wallet/init.cpp
@@ -17,7 +17,7 @@ std::string GetWalletHelpString(bool showDebug)
 {
     std::string strUsage = HelpMessageGroup(_("Wallet options:"));
     strUsage += HelpMessageOpt("-addresstype", strprintf(_("What type of addresses to use (\"legacy\", \"p2sh-segwit\", or \"bech32\", default: \"%s\")"), FormatOutputType(OUTPUT_TYPE_DEFAULT)));
-    strUsage += HelpMessageOpt("-changetype", _("What type of change to use (\"legacy\", \"p2sh-segwit\", or \"bech32\", default is same as -addresstype)"));
+    strUsage += HelpMessageOpt("-changetype", _("What type of change to use (\"legacy\", \"p2sh-segwit\", or \"bech32\"). Default is same as -addresstype, except when -addresstype=p2sh-segwit a native segwit output is used when sending to a native segwit address)"));
     strUsage += HelpMessageOpt("-disablewallet", _("Do not load the wallet and disable wallet RPC calls"));
     strUsage += HelpMessageOpt("-keypool=<n>", strprintf(_("Set key pool size to <n> (default: %u)"), DEFAULT_KEYPOOL_SIZE));
     strUsage += HelpMessageOpt("-fallbackfee=<amt>", strprintf(_("A fee rate (in %s/kB) that will be used when fee estimation has insufficient data (default: %s)"),
@@ -182,8 +182,10 @@ bool WalletParameterInteraction()
         return InitError(strprintf(_("Unknown address type '%s'"), gArgs.GetArg("-addresstype", "")));
     }
 
-    g_change_type = ParseOutputType(gArgs.GetArg("-changetype", ""), g_address_type);
-    if (g_change_type == OUTPUT_TYPE_NONE) {
+    // If changetype is set in config file or parameter, check that it's valid.
+    // Default to OUTPUT_TYPE_NONE if not set.
+    g_change_type = ParseOutputType(gArgs.GetArg("-changetype", ""), OUTPUT_TYPE_NONE);
+    if (g_change_type == OUTPUT_TYPE_NONE && !gArgs.GetArg("-changetype", "").empty()) {
         return InitError(strprintf(_("Unknown change type '%s'"), gArgs.GetArg("-changetype", "")));
     }