Merge #18278: interfaces: Describe and follow some code conventions

3dc27a15242a22b5301904375e5880372e9b7f4d doc: Add internal interface conventions to developer notes (Russell Yanofsky)
1dca9dc4c772fa0a4ec52c4d88b7cd3d243aea7b refactor: Change createWallet, fillPSBT argument order (Russell Yanofsky)
96dfe5ced64979e51649d20555aa182defc80119 refactor: Change Chain::broadcastTransaction param order (Russell Yanofsky)
6ceb21909ce66b7b4762a855889acd46bb6b77f3 refactor: Rename Chain::Notifications methods to be consistent with other interfaces methods (Russell Yanofsky)
1c2ab1a6d29f2c6c065dae4f4a4e2ad1286311b3 refactor: Rename Node::disconnect methods (Russell Yanofsky)
77e4b0657298c715c835d8d2eb11e173852e6815 refactor: Get rid of Wallet::IsWalletFlagSet method (Russell Yanofsky)

Pull request description:

  This PR is part of the [process separation project](https://github.com/bitcoin/bitcoin/projects/10).

  This PR doesn't change behavior at all, it just cleans up code in [`src/interfaces`](https://github.com/bitcoin/bitcoin/tree/master/src/interfaces) to simplify #10102, and [documents](https://github.com/ryanofsky/bitcoin/blob/pr/ipc-conv/doc/developer-notes.md#internal-interface-guidelines) coding conventions there better

ACKs for top commit:
  hebasto:
    re-ACK 3dc27a15242a22b5301904375e5880372e9b7f4d, the only change since the [previous](https://github.com/bitcoin/bitcoin/pull/18278#pullrequestreview-372582146) review is rebasing.
  MarcoFalke:
    ACK 3dc27a15242a22b5301904375e5880372e9b7f4d 🕍

Tree-SHA512: 62e6a0f2488e3924e559d2074ed460b92e7a0a5d98eab492221cb20d59d04bbe32aef2a8aeba5e4ea9168cfa91acd5bc973dce6677be0180bd7a919354df53ed

2 files changed, 16 insertions, 16 deletions

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 01aadcdd6..9a972feba 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -344,7 +344,7 @@ bool CWallet::ChangeWalletPassphrase(const SecureString& strOldWalletPassphrase,
     return false;
 }
 
-void CWallet::ChainStateFlushed(const CBlockLocator& loc)
+void CWallet::chainStateFlushed(const CBlockLocator& loc)
 {
     WalletBatch batch(*database);
     batch.WriteBestBlock(loc);
@@ -1089,7 +1089,7 @@ void CWallet::SyncTransaction(const CTransactionRef& ptx, CWalletTx::Confirmatio
     MarkInputsDirty(ptx);
 }
 
-void CWallet::TransactionAddedToMempool(const CTransactionRef& ptx) {
+void CWallet::transactionAddedToMempool(const CTransactionRef& ptx) {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
     CWalletTx::Confirmation confirm(CWalletTx::Status::UNCONFIRMED, /* block_height */ 0, {}, /* nIndex */ 0);
@@ -1101,7 +1101,7 @@ void CWallet::TransactionAddedToMempool(const CTransactionRef& ptx) {
     }
 }
 
-void CWallet::TransactionRemovedFromMempool(const CTransactionRef &ptx) {
+void CWallet::transactionRemovedFromMempool(const CTransactionRef &ptx) {
     LOCK(cs_wallet);
     auto it = mapWallet.find(ptx->GetHash());
     if (it != mapWallet.end()) {
@@ -1109,7 +1109,7 @@ void CWallet::TransactionRemovedFromMempool(const CTransactionRef &ptx) {
     }
 }
 
-void CWallet::BlockConnected(const CBlock& block, int height)
+void CWallet::blockConnected(const CBlock& block, int height)
 {
     const uint256& block_hash = block.GetHash();
     auto locked_chain = chain().lock();
@@ -1120,11 +1120,11 @@ void CWallet::BlockConnected(const CBlock& block, int height)
     for (size_t index = 0; index < block.vtx.size(); index++) {
         CWalletTx::Confirmation confirm(CWalletTx::Status::CONFIRMED, height, block_hash, index);
         SyncTransaction(block.vtx[index], confirm);
-        TransactionRemovedFromMempool(block.vtx[index]);
+        transactionRemovedFromMempool(block.vtx[index]);
     }
 }
 
-void CWallet::BlockDisconnected(const CBlock& block, int height)
+void CWallet::blockDisconnected(const CBlock& block, int height)
 {
     auto locked_chain = chain().lock();
     LOCK(cs_wallet);
@@ -1141,7 +1141,7 @@ void CWallet::BlockDisconnected(const CBlock& block, int height)
     }
 }
 
-void CWallet::UpdatedBlockTip()
+void CWallet::updatedBlockTip()
 {
     m_best_block_time = GetTime();
 }
@@ -1785,7 +1785,7 @@ bool CWalletTx::SubmitMemoryPoolAndRelay(std::string& err_string, bool relay)
     // Irrespective of the failure reason, un-marking fInMempool
     // out-of-order is incorrect - it should be unmarked when
     // TransactionRemovedFromMempool fires.
-    bool ret = pwallet->chain().broadcastTransaction(tx, err_string, pwallet->m_default_max_tx_fee, relay);
+    bool ret = pwallet->chain().broadcastTransaction(tx, pwallet->m_default_max_tx_fee, relay, err_string);
     fInMempool |= ret;
     return ret;
 }
@@ -3875,7 +3875,7 @@ std::shared_ptr<CWallet> CWallet::CreateWalletFromFile(interfaces::Chain& chain,
         }
 
         auto locked_chain = chain.lock();
-        walletInstance->ChainStateFlushed(locked_chain->getTipLocator());
+        walletInstance->chainStateFlushed(locked_chain->getTipLocator());
     } else if (wallet_creation_flags & WALLET_FLAG_DISABLE_PRIVATE_KEYS) {
         // Make it impossible to disable private keys after creation
         error = strprintf(_("Error loading %s: Private keys can only be disabled during creation").translated, walletFile);
@@ -4056,7 +4056,7 @@ std::shared_ptr<CWallet> CWallet::CreateWalletFromFile(interfaces::Chain& chain,
                 return nullptr;
             }
         }
-        walletInstance->ChainStateFlushed(locked_chain->getTipLocator());
+        walletInstance->chainStateFlushed(locked_chain->getTipLocator());
         walletInstance->database->IncrementUpdateCounter();
 
         // Restore wallet transaction metadata after -zapwallettxes=1
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 1fb72c83c..75fd14a80 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -875,10 +875,10 @@ public:
     void MarkDirty();
     bool AddToWallet(const CWalletTx& wtxIn, bool fFlushOnClose=true);
     void LoadToWallet(CWalletTx& wtxIn) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
-    void TransactionAddedToMempool(const CTransactionRef& tx) override;
-    void BlockConnected(const CBlock& block, int height) override;
-    void BlockDisconnected(const CBlock& block, int height) override;
-    void UpdatedBlockTip() override;
+    void transactionAddedToMempool(const CTransactionRef& tx) override;
+    void blockConnected(const CBlock& block, int height) override;
+    void blockDisconnected(const CBlock& block, int height) override;
+    void updatedBlockTip() override;
     int64_t RescanFromTime(int64_t startTime, const WalletRescanReserver& reserver, bool update);
 
     struct ScanResult {
@@ -897,7 +897,7 @@ public:
         uint256 last_failed_block;
     };
     ScanResult ScanForWalletTransactions(const uint256& first_block, const uint256& last_block, const WalletRescanReserver& reserver, bool fUpdate);
-    void TransactionRemovedFromMempool(const CTransactionRef &ptx) override;
+    void transactionRemovedFromMempool(const CTransactionRef &ptx) override;
     void ReacceptWalletTransactions() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     void ResendWalletTransactions();
     struct Balance {
@@ -1033,7 +1033,7 @@ public:
     bool IsAllFromMe(const CTransaction& tx, const isminefilter& filter) const;
     CAmount GetCredit(const CTransaction& tx, const isminefilter& filter) const;
     CAmount GetChange(const CTransaction& tx) const;
-    void ChainStateFlushed(const CBlockLocator& loc) override;
+    void chainStateFlushed(const CBlockLocator& loc) override;
 
     DBErrors LoadWallet(bool& fFirstRunRet);
     DBErrors ZapWalletTx(std::vector<CWalletTx>& vWtx);