Merge bitcoin/bitcoin#25784: Wallet: Document expectations for AddWalletFlags (now InitWalletFlags) correctly

0cb6d2aec63aec76a517b8da621a3c53ab432632 Bugfix: Wallet: Document expectations for AddWalletFlags (now InitWalletFlags) correctly (Luke Dashjr)

Pull request description:

  Includes some slight refactoring (return type changed, current status checked)

ACKs for top commit:
  achow101:
    ACK 0cb6d2aec63aec76a517b8da621a3c53ab432632
  w0xlt:
    ACK https://github.com/bitcoin/bitcoin/pull/25784/commits/0cb6d2aec63aec76a517b8da621a3c53ab432632
  ryanofsky:
    Code review ACK 0cb6d2aec63aec76a517b8da621a3c53ab432632. This is a clarifying change, and should prevent the InitWalletFlags method being called incorrectly. I left a comment suggestion, but feel free to ignore it.

Tree-SHA512: fa18e9471b5e89d35cbc01526e6d4dbe4eee8faa9646847248909af1751b33014a6f9a42fe70a1331c0d73adea79008b8fc3ae2b51a641eba3e36d5c631327f6

3 files changed, 11 insertions, 6 deletions

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index de787ae421..3d989d90f8 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1526,16 +1526,20 @@ bool CWallet::LoadWalletFlags(uint64_t flags)
     return true;
 }
 
-bool CWallet::AddWalletFlags(uint64_t flags)
+void CWallet::InitWalletFlags(uint64_t flags)
 {
     LOCK(cs_wallet);
+
     // We should never be writing unknown non-tolerable wallet flags
     assert(((flags & KNOWN_WALLET_FLAGS) >> 32) == (flags >> 32));
+    // This should only be used once, when creating a new wallet - so current flags are expected to be blank
+    assert(m_wallet_flags == 0);
+
     if (!WalletBatch(GetDatabase()).WriteWalletFlags(flags)) {
         throw std::runtime_error(std::string(__func__) + ": writing wallet flags failed");
     }
 
-    return LoadWalletFlags(flags);
+    if (!LoadWalletFlags(flags)) assert(false);
 }
 
 // Helper for producing a max-sized low-S low-R signature (eg 71 bytes)
@@ -2832,7 +2836,7 @@ std::shared_ptr<CWallet> CWallet::Create(WalletContext& context, const std::stri
         // ensure this wallet.dat can only be opened by clients supporting HD with chain split and expects no default key
         walletInstance->SetMinVersion(FEATURE_LATEST);
 
-        walletInstance->AddWalletFlags(wallet_creation_flags);
+        walletInstance->InitWalletFlags(wallet_creation_flags);
 
         // Only create LegacyScriptPubKeyMan when not descriptor wallet
         if (!walletInstance->IsWalletFlagSet(WALLET_FLAG_DESCRIPTORS)) {
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 3a46d0a987..934811dee1 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -806,8 +806,9 @@ public:
     bool IsWalletFlagSet(uint64_t flag) const override;
 
     /** overwrite all flags by the given uint64_t
-       returns false if unknown, non-tolerable flags are present */
-    bool AddWalletFlags(uint64_t flags);
+       flags must be uninitialised (or 0)
+       only known flags may be present */
+    void InitWalletFlags(uint64_t flags);
     /** Loads the flags into the wallet. (used by LoadWallet) */
     bool LoadWalletFlags(uint64_t flags);
 
diff --git a/src/wallet/wallettool.cpp b/src/wallet/wallettool.cpp
index 769175b5a8..e991bc0814 100644
--- a/src/wallet/wallettool.cpp
+++ b/src/wallet/wallettool.cpp
@@ -34,7 +34,7 @@ static void WalletCreate(CWallet* wallet_instance, uint64_t wallet_creation_flag
     LOCK(wallet_instance->cs_wallet);
 
     wallet_instance->SetMinVersion(FEATURE_LATEST);
-    wallet_instance->AddWalletFlags(wallet_creation_flags);
+    wallet_instance->InitWalletFlags(wallet_creation_flags);
 
     if (!wallet_instance->IsWalletFlagSet(WALLET_FLAG_DESCRIPTORS)) {
         auto spk_man = wallet_instance->GetOrCreateLegacyScriptPubKeyMan();