Merge #10500: Avoid CWalletTx copies in GetAddressBalances and GetAdd…

…ressGroupings

Summary:
b9b814a Avoid CWalletTx copies in GetAddressBalances and GetAddressGroupings (Russell Yanofsky)

Tree-SHA512: 96a0612ca460ba1bfb3921f3aa348400fd3afa12c40f2ca1f3f04068b1574fe824d577e0123013d8898a4990084316dc1dfb541331849f0996ceff7f4eb25e6b

Backport of Core PR10500
bitcoin/bitcoin#10500

Test Plan:
  make check
  test_runner.py

Reviewers: jasonbcox, Fabien, deadalnix, O1 Bitcoin ABC, #bitcoin_abc

Reviewed By: jasonbcox, O1 Bitcoin ABC, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D3239

src/wallet/wallet.cpp

@@ -3726,8 +3726,8 @@ std::map<CTxDestination, Amount> CWallet::GetAddressBalances() {
     std::map<CTxDestination, Amount> balances;
 
     LOCK(cs_wallet);
-    for (std::pair<TxId, CWalletTx> walletEntry : mapWallet) {
-        CWalletTx *pcoin = &walletEntry.second;
+    for (const auto &walletEntry : mapWallet) {
+        const CWalletTx *pcoin = &walletEntry.second;
 
         if (!pcoin->IsTrusted()) {
             continue;
@@ -3772,8 +3772,8 @@ std::set<std::set<CTxDestination>> CWallet::GetAddressGroupings() {
     std::set<std::set<CTxDestination>> groupings;
     std::set<CTxDestination> grouping;
 
-    for (std::pair<uint256, CWalletTx> walletEntry : mapWallet) {
-        CWalletTx *pcoin = &walletEntry.second;
+    for (const auto &walletEntry : mapWallet) {
+        const CWalletTx *pcoin = &walletEntry.second;
 
         if (pcoin->tx->vin.size() > 0) {
             bool any_mine = false;