Merge bitcoin/bitcoin#25656: refactor: wallet: return util::Result from `GetReservedDestination` methods

76b3c37fcb93b4bcb047e0500fdaa605160e25d5 refactor: wallet: return util::Result from `GetReservedDestination` methods (Sebastian Falbesoner)

Pull request description:

  This PR is a follow-up to #25218, as suggested in comment https://github.com/bitcoin/bitcoin/pull/25218#discussion_r907710067. The interfaces of the methods `ReserveDestination::GetReservedDestination`, `{Legacy,Descriptor,}ScriptPubKeyMan::GetReservedDestination` are improved by returning `util::Result<CTxDestination>` instead of `bool` in order to get rid of the two `CTxDestination&` and `bilingual_str&` out-parameters.

ACKs for top commit:
  furszy:
    ACK 76b3c37f

Tree-SHA512: bf15560a88d645bcf8768024013d36012cd65caaa4a613e8a055dfd8f29cb4a219c19084606992bad177920cdca3a732ec168e9b9526f9295491f2cf79cc6815

1 files changed, 9 insertions, 16 deletions

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 0a2997b3f1..de1078e646 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2359,15 +2359,11 @@ util::Result<CTxDestination> CWallet::GetNewChangeDestination(const OutputType t
 {
     LOCK(cs_wallet);
 
-    CTxDestination dest;
-    bilingual_str error;
     ReserveDestination reservedest(this, type);
-    if (!reservedest.GetReservedDestination(dest, true, error)) {
-        return util::Error{error};
-    }
+    auto op_dest = reservedest.GetReservedDestination(true);
+    if (op_dest) reservedest.KeepDestination();
 
-    reservedest.KeepDestination();
-    return dest;
+    return op_dest;
 }
 
 std::optional<int64_t> CWallet::GetOldestKeyPoolTime() const
@@ -2437,27 +2433,24 @@ std::set<std::string> CWallet::ListAddrBookLabels(const std::string& purpose) co
     return label_set;
 }
 
-bool ReserveDestination::GetReservedDestination(CTxDestination& dest, bool internal, bilingual_str& error)
+util::Result<CTxDestination> ReserveDestination::GetReservedDestination(bool internal)
 {
     m_spk_man = pwallet->GetScriptPubKeyMan(type, internal);
     if (!m_spk_man) {
-        error = strprintf(_("Error: No %s addresses available."), FormatOutputType(type));
-        return false;
+        return util::Error{strprintf(_("Error: No %s addresses available."), FormatOutputType(type))};
     }
 
-
     if (nIndex == -1)
     {
         m_spk_man->TopUp();
 
         CKeyPool keypool;
-        if (!m_spk_man->GetReservedDestination(type, internal, address, nIndex, keypool, error)) {
-            return false;
-        }
+        auto op_address = m_spk_man->GetReservedDestination(type, internal, nIndex, keypool);
+        if (!op_address) return op_address;
+        address = *op_address;
         fInternal = keypool.fInternal;
     }
-    dest = address;
-    return true;
+    return address;
 }
 
 void ReserveDestination::KeepDestination()