Merge #20584: Declare de facto const reference variables/member functions as const

31b136e5802e1b1e5f9a9589736afe0652f34da2 Don't declare de facto const reference variables as non-const (practicalswift)
1c65c075ee4c7f98d9c1fac5ed7576b96374d4e9 Don't declare de facto const member functions as non-const (practicalswift)

Pull request description:

  _Meta: This is the second and final part of the `const` refactoring series (part one: #20581). **I promise: no more refactoring PRs from me in a while! :)** I'll now go back to focusing on fuzzing/hardening!_

  Changes in this PR:
  * Don't declare de facto const member functions as non-const
  * Don't declare de facto const reference variables as non-const

  Awards for finding candidates for the above changes go to:
  * `clang-tidy`'s [`readability-make-member-function-const`](https://clang.llvm.org/extra/clang-tidy/checks/readability-make-member-function-const.html)  check ([list of `clang-tidy` checks](https://clang.llvm.org/extra/clang-tidy/checks/list.html))
  * `cppcheck`'s `constVariable` check ([list of `cppcheck` checks](https://sourceforge.net/p/cppcheck/wiki/ListOfChecks/))

  See #18920 for instructions on how to analyse Bitcoin Core using Clang Static Analysis, `clang-tidy` and `cppcheck`.

ACKs for top commit:
  ajtowns:
    ACK 31b136e5802e1b1e5f9a9589736afe0652f34da2
  jonatack:
    ACK 31b136e5802e1b1e5f9a9589736afe0652f34da2
  theStack:
    ACK 31b136e5802e1b1e5f9a9589736afe0652f34da2 :snowflake:

Tree-SHA512: f58f8f00744219426874379e9f3e9331132b9b48e954d24f3a85cbb858fdcc98009ed42ef7e7b4619ae8af9fc240a6d8bfc1c438db2e97b0ecd722a80dcfeffe

3 files changed, 5 insertions, 5 deletions

diff --git a/src/wallet/feebumper.cpp b/src/wallet/feebumper.cpp
index aea5e8e60a..5e319d4f95 100644
--- a/src/wallet/feebumper.cpp
+++ b/src/wallet/feebumper.cpp
@@ -256,7 +256,7 @@ Result CommitTransaction(CWallet& wallet, const uint256& txid, CMutableTransacti
         errors.push_back(Untranslated("Invalid or non-wallet transaction id"));
         return Result::MISC_ERROR;
     }
-    CWalletTx& oldWtx = it->second;
+    const CWalletTx& oldWtx = it->second;
 
     // make sure the transaction still has no descendants and hasn't been mined in the meantime
     Result result = PreconditionChecks(wallet, oldWtx, errors);
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index ed5de6e852..0bcbff3b2f 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -570,7 +570,7 @@ void CWallet::AddToSpends(const uint256& wtxid)
 {
     auto it = mapWallet.find(wtxid);
     assert(it != mapWallet.end());
-    CWalletTx& thisTx = it->second;
+    const CWalletTx& thisTx = it->second;
     if (thisTx.IsCoinBase()) // Coinbases don't spend anything!
         return;
 
@@ -1054,7 +1054,7 @@ bool CWallet::AbandonTransaction(const uint256& hashTx)
     // Can't mark abandoned if confirmed or in mempool
     auto it = mapWallet.find(hashTx);
     assert(it != mapWallet.end());
-    CWalletTx& origtx = it->second;
+    const CWalletTx& origtx = it->second;
     if (origtx.GetDepthInMainChain() != 0 || origtx.InMempool()) {
         return false;
     }
@@ -2709,7 +2709,7 @@ static uint32_t GetLocktimeForNewTransaction(interfaces::Chain& chain, const uin
     return locktime;
 }
 
-OutputType CWallet::TransactionChangeType(const Optional<OutputType>& change_type, const std::vector<CRecipient>& vecSend)
+OutputType CWallet::TransactionChangeType(const Optional<OutputType>& change_type, const std::vector<CRecipient>& vecSend) const
 {
     // If -changetype is specified, always use that change type.
     if (change_type) {
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index e6beb111fb..e3eae1dd95 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -930,7 +930,7 @@ public:
     Balance GetBalance(int min_depth = 0, bool avoid_reuse = true) const;
     CAmount GetAvailableBalance(const CCoinControl* coinControl = nullptr) const;
 
-    OutputType TransactionChangeType(const Optional<OutputType>& change_type, const std::vector<CRecipient>& vecSend);
+    OutputType TransactionChangeType(const Optional<OutputType>& change_type, const std::vector<CRecipient>& vecSend) const;
 
     /**
      * Insert additional inputs into the transaction by