1 files changed, 69 insertions, 38 deletions

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index b00fa851fd..60d60d1e81 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -603,12 +603,12 @@ bool CWallet::EncryptWallet(const SecureString& strWalletPassphrase)
     CKeyingMaterial _vMasterKey;
 
     _vMasterKey.resize(WALLET_CRYPTO_KEY_SIZE);
-    GetStrongRandBytes(&_vMasterKey[0], WALLET_CRYPTO_KEY_SIZE);
+    GetStrongRandBytes(_vMasterKey.data(), WALLET_CRYPTO_KEY_SIZE);
 
     CMasterKey kMasterKey;
 
     kMasterKey.vchSalt.resize(WALLET_CRYPTO_SALT_SIZE);
-    GetStrongRandBytes(&kMasterKey.vchSalt[0], WALLET_CRYPTO_SALT_SIZE);
+    GetStrongRandBytes(kMasterKey.vchSalt.data(), WALLET_CRYPTO_SALT_SIZE);
 
     CCrypter crypter;
     int64_t nStartTime = GetTimeMillis();
@@ -1784,7 +1784,7 @@ CWallet::ScanResult CWallet::ScanForWalletTransactions(const uint256& start_bloc
     WalletLogPrintf("Rescan started from block %s...\n", start_block.ToString());
 
     fAbortRescan = false;
-    ShowProgress(strprintf("%s " + _("Rescanning...").translated, GetDisplayName()), 0); // show rescan progress in GUI as dialog or on splashscreen, if -rescan on startup
+    ShowProgress(strprintf("%s " + _("Rescanning…").translated, GetDisplayName()), 0); // show rescan progress in GUI as dialog or on splashscreen, if -rescan on startup
     uint256 tip_hash = WITH_LOCK(cs_wallet, return GetLastBlockHash());
     uint256 end_hash = tip_hash;
     if (max_height) chain().findAncestorByHeight(tip_hash, *max_height, FoundBlock().hash(end_hash));
@@ -1799,7 +1799,7 @@ CWallet::ScanResult CWallet::ScanForWalletTransactions(const uint256& start_bloc
             m_scanning_progress = 0;
         }
         if (block_height % 100 == 0 && progress_end - progress_begin > 0.0) {
-            ShowProgress(strprintf("%s " + _("Rescanning...").translated, GetDisplayName()), std::max(1, std::min(99, (int)(m_scanning_progress * 100))));
+            ShowProgress(strprintf("%s " + _("Rescanning…").translated, GetDisplayName()), std::max(1, std::min(99, (int)(m_scanning_progress * 100))));
         }
         if (GetTime() >= nNow + 60) {
             nNow = GetTime();
@@ -1861,7 +1861,7 @@ CWallet::ScanResult CWallet::ScanForWalletTransactions(const uint256& start_bloc
             }
         }
     }
-    ShowProgress(strprintf("%s " + _("Rescanning...").translated, GetDisplayName()), 100); // hide progress dialog in GUI
+    ShowProgress(strprintf("%s " + _("Rescanning…").translated, GetDisplayName()), 100); // hide progress dialog in GUI
     if (block_height && fAbortRescan) {
         WalletLogPrintf("Rescan aborted at block %d. Progress=%f\n", block_height, progress_current);
         result.status = ScanResult::USER_ABORT;
@@ -2478,7 +2478,7 @@ bool CWallet::SelectCoins(const std::vector<COutput>& vAvailableCoins, const CAm
         }
     }
 
-    // remove preset inputs from vCoins
+    // remove preset inputs from vCoins so that Coin Selection doesn't pick them.
     for (std::vector<COutput>::iterator it = vCoins.begin(); it != vCoins.end() && coin_control.HasSelected();)
     {
         if (setPresetCoins.count(it->GetInputCoin()))
@@ -2490,9 +2490,9 @@ bool CWallet::SelectCoins(const std::vector<COutput>& vAvailableCoins, const CAm
     unsigned int limit_ancestor_count = 0;
     unsigned int limit_descendant_count = 0;
     chain().getPackageLimits(limit_ancestor_count, limit_descendant_count);
-    size_t max_ancestors = (size_t)std::max<int64_t>(1, limit_ancestor_count);
-    size_t max_descendants = (size_t)std::max<int64_t>(1, limit_descendant_count);
-    bool fRejectLongChains = gArgs.GetBoolArg("-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS);
+    const size_t max_ancestors = (size_t)std::max<int64_t>(1, limit_ancestor_count);
+    const size_t max_descendants = (size_t)std::max<int64_t>(1, limit_descendant_count);
+    const bool fRejectLongChains = gArgs.GetBoolArg("-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS);
 
     // form groups from remaining coins; note that preset coins will not
     // automatically have their associated (same address) coins included
@@ -2502,16 +2502,60 @@ bool CWallet::SelectCoins(const std::vector<COutput>& vAvailableCoins, const CAm
         // explicitly shuffling the outputs before processing
         Shuffle(vCoins.begin(), vCoins.end(), FastRandomContext());
     }
-    bool res = value_to_select <= 0 ||
-        SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(1, 6, 0), vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used) ||
-        SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(1, 1, 0), vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used) ||
-        (m_spend_zero_conf_change && SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(0, 1, 2), vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) ||
-        (m_spend_zero_conf_change && SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(0, 1, std::min((size_t)4, max_ancestors/3), std::min((size_t)4, max_descendants/3)), vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) ||
-        (m_spend_zero_conf_change && SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(0, 1, max_ancestors/2, max_descendants/2), vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) ||
-        (m_spend_zero_conf_change && SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(0, 1, max_ancestors-1, max_descendants-1, true /* include_partial_groups */), vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) ||
-        (m_spend_zero_conf_change && !fRejectLongChains && SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(0, 1, std::numeric_limits<uint64_t>::max(), std::numeric_limits<uint64_t>::max(), true /* include_partial_groups */), vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used));
 
-    // because SelectCoinsMinConf clears the setCoinsRet, we now add the possible inputs to the coinset
+    // Coin Selection attempts to select inputs from a pool of eligible UTXOs to fund the
+    // transaction at a target feerate. If an attempt fails, more attempts may be made using a more
+    // permissive CoinEligibilityFilter.
+    const bool res = [&] {
+        // Pre-selected inputs already cover the target amount.
+        if (value_to_select <= 0) return true;
+
+        // If possible, fund the transaction with confirmed UTXOs only. Prefer at least six
+        // confirmations on outputs received from other wallets and only spend confirmed change.
+        if (SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(1, 6, 0), vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) return true;
+        if (SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(1, 1, 0), vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) return true;
+
+        // Fall back to using zero confirmation change (but with as few ancestors in the mempool as
+        // possible) if we cannot fund the transaction otherwise.
+        if (m_spend_zero_conf_change) {
+            if (SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(0, 1, 2), vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) return true;
+            if (SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(0, 1, std::min((size_t)4, max_ancestors/3), std::min((size_t)4, max_descendants/3)),
+                                   vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) {
+                return true;
+            }
+            if (SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(0, 1, max_ancestors/2, max_descendants/2),
+                                   vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) {
+                return true;
+            }
+            // If partial groups are allowed, relax the requirement of spending OutputGroups (groups
+            // of UTXOs sent to the same address, which are obviously controlled by a single wallet)
+            // in their entirety.
+            if (SelectCoinsMinConf(value_to_select, CoinEligibilityFilter(0, 1, max_ancestors-1, max_descendants-1, true /* include_partial_groups */),
+                                   vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) {
+                return true;
+            }
+            // Try with unsafe inputs if they are allowed. This may spend unconfirmed outputs
+            // received from other wallets.
+            if (coin_control.m_include_unsafe_inputs
+                && SelectCoinsMinConf(value_to_select,
+                    CoinEligibilityFilter(0 /* conf_mine */, 0 /* conf_theirs */, max_ancestors-1, max_descendants-1, true /* include_partial_groups */),
+                    vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) {
+                return true;
+            }
+            // Try with unlimited ancestors/descendants. The transaction will still need to meet
+            // mempool ancestor/descendant policy to be accepted to mempool and broadcasted, but
+            // OutputGroups use heuristics that may overestimate ancestor/descendant counts.
+            if (!fRejectLongChains && SelectCoinsMinConf(value_to_select,
+                                      CoinEligibilityFilter(0, 1, std::numeric_limits<uint64_t>::max(), std::numeric_limits<uint64_t>::max(), true /* include_partial_groups */),
+                                      vCoins, setCoinsRet, nValueRet, coin_selection_params, bnb_used)) {
+                return true;
+            }
+        }
+        // Coin Selection failed.
+        return false;
+    }();
+
+    // SelectCoinsMinConf clears setCoinsRet, so add the preset inputs from coin_control to the coinset
     util::insert(setCoinsRet, setPresetCoins);
 
     // add preset inputs to the total value selected
@@ -2799,7 +2843,7 @@ bool CWallet::CreateTransactionInternal(
         txNew.nLockTime = GetLocktimeForNewTransaction(chain(), GetLastBlockHash(), GetLastBlockHeight());
         {
             std::vector<COutput> vAvailableCoins;
-            AvailableCoins(vAvailableCoins, true, &coin_control, 1, MAX_MONEY, MAX_MONEY, 0);
+            AvailableCoins(vAvailableCoins, !coin_control.m_include_unsafe_inputs, &coin_control, 1, MAX_MONEY, MAX_MONEY, 0);
             CoinSelectionParams coin_selection_params; // Parameters for coin selection, init with dummy
             coin_selection_params.m_avoid_partial_spends = coin_control.m_avoid_partial_spends;
 
@@ -3594,19 +3638,6 @@ void ReserveDestination::ReturnDestination()
     address = CNoDestination();
 }
 
-#ifdef ENABLE_EXTERNAL_SIGNER
-ExternalSigner CWallet::GetExternalSigner()
-{
-    const std::string command = gArgs.GetArg("-signer", "");
-    if (command == "") throw std::runtime_error(std::string(__func__) + ": restart bitcoind with -signer=<cmd>");
-    std::vector<ExternalSigner> signers;
-    ExternalSigner::Enumerate(command, signers, Params().NetworkIDString());
-    if (signers.empty()) throw std::runtime_error(std::string(__func__) + ": No external signers found");
-    // TODO: add fingerprint argument in case of multiple signers
-    return signers[0];
-}
-#endif
-
 bool CWallet::DisplayAddress(const CTxDestination& dest)
 {
 #ifdef ENABLE_EXTERNAL_SIGNER
@@ -3619,7 +3650,7 @@ bool CWallet::DisplayAddress(const CTxDestination& dest)
     if (signer_spk_man == nullptr) {
         return false;
     }
-    ExternalSigner signer = GetExternalSigner(); // TODO: move signer in spk_man
+    ExternalSigner signer = ExternalSignerScriptPubKeyMan::GetExternalSigner();
     return signer_spk_man->DisplayAddress(scriptPubKey, signer);
 #else
     return false;
@@ -3858,7 +3889,7 @@ std::shared_ptr<CWallet> CWallet::Create(interfaces::Chain& chain, const std::st
 {
     const std::string& walletFile = database->Filename();
 
-    chain.initMessage(_("Loading wallet...").translated);
+    chain.initMessage(_("Loading wallet…").translated);
 
     int64_t nStart = GetTimeMillis();
     bool fFirstRun = true;
@@ -4108,7 +4139,7 @@ std::shared_ptr<CWallet> CWallet::Create(interfaces::Chain& chain, const std::st
             }
         }
 
-        chain.initMessage(_("Rescanning...").translated);
+        chain.initMessage(_("Rescanning…").translated);
         walletInstance->WalletLogPrintf("Rescanning last %i blocks (from block %i)...\n", *tip_height - rescan_height, rescan_height);
 
         // No need to read and scan block if block was created before
@@ -4516,7 +4547,7 @@ void CWallet::LoadDescriptorScriptPubKeyMan(uint256 id, WalletDescriptor& desc)
         auto spk_manager = std::unique_ptr<ScriptPubKeyMan>(new ExternalSignerScriptPubKeyMan(*this, desc));
         m_spk_managers[id] = std::move(spk_manager);
 #else
-        throw std::runtime_error(std::string(__func__) + ": Configure with --enable-external-signer to use external signer wallets");
+        throw std::runtime_error(std::string(__func__) + ": Compiled without external signing support (required for external signing)");
 #endif
     } else {
         auto spk_manager = std::unique_ptr<ScriptPubKeyMan>(new DescriptorScriptPubKeyMan(*this, desc));
@@ -4585,8 +4616,8 @@ void CWallet::SetupDescriptorScriptPubKeyMans()
             }
         }
 #else
-        throw std::runtime_error(std::string(__func__) + ": Wallets with external signers require Boost::Process library.");
-#endif
+        throw std::runtime_error(std::string(__func__) + ": Compiled without external signing support (required for external signing)");
+#endif // ENABLE_EXTERNAL_SIGNER
     }
 }