`LockAnnotation lock(::cs_main)` is a guarantee to the compiler thread analysis that `::cs_main` is locked (when it couldn't be determined otherwise).

Despite being annotated with the locking guarantee ...

https://github.com/bitcoin/bitcoin/blob/65526fc8666fef35ef908dbc225f706bef642c7e/src/interfaces/chain.cpp#L134-L138

... `getTipLocator()` reads `chainActive` (via `::ChainActive()`) without holding `cs_main`.

This can be verified by adding the following `AssertLockHeld(cs_main)`:

```
$ git diff
diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index 59623284d..9fc693a0f 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -134,6 +134,7 @@ class LockImpl : public Chain::Lock
     CBlockLocator getTipLocator() override
     {
         LockAnnotation lock(::cs_main);
+        AssertLockHeld(::cs_main);
         return ::ChainActive().GetLocator();
     }
     Optional<int> findLocatorFork(const CBlockLocator& locator) override
$ make check
../build-aux/test-driver: line 107: 12881 Aborted                 "$@" > $log_file 2>&1
FAIL: qt/test/test_bitcoin-qt
```
if (!meta.hd_seed_id.IsNull() && !meta.has_key_origin && meta.hdKeypath != "s") { 
            CKey key;
            GetKey(meta.hd_seed_id, key);
            CExtKey masterKey;
            masterKey.SetSeed(key.begin(), key.size());
            
            CKeyID master_id = masterKey.key.GetPubKey().GetID();
            std::copy(master_id.begin(), master_id.begin() + 4, meta.key_origin.fingerprint);
            if (!ParseHDKeypath(meta.hdKeypath, meta.key_origin.path)) {
                throw std::runtime_error("Invalid stored hdKeypath");
            }
            meta.has_key_origin = true;
            if (meta.nVersion < CKeyMetadata::VERSION_WITH_KEY_ORIGIN) {
                meta.nVersion = CKeyMetadata::VERSION_WITH_KEY_ORIGIN;
            }
            
            CPubKey pubkey;
            if (GetPubKey(meta_pair.first, pubkey)) {
                batch->WriteKeyMetadata(meta, pubkey, true);
                if (++cnt % 1000 == 0) {
                    
                    batch.reset(new WalletBatch(*database));
                }
            }
        }
    }
    batch.reset(); 
    SetWalletFlag(WALLET_FLAG_KEY_ORIGIN_METADATA);
}
bool CWallet::LoadCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret)