Use CWallet::m_last_block_processed_height in GetDepthInMainChain

Avoid to lock chain to query state thanks to tracking last block
height in CWallet.

Adaptation of btc@0ff03871add000f8b4d8f82aeb168eed2fc9dc5f

src/wallet/wallet.cpp

@@ -4321,24 +4321,11 @@ CWalletKey::CWalletKey(int64_t nExpires)
 
 int CWalletTx::GetDepthInMainChain() const
 {
+    assert(pwallet != nullptr);
+    AssertLockHeld(pwallet->cs_wallet);
     if (isUnconfirmed() || isAbandoned()) return 0;
-    AssertLockHeld(cs_main);
-    int nResult;
-
-    // Find the block it claims to be in
-    BlockMap::iterator mi = mapBlockIndex.find(m_confirm.hashBlock);
-    if (mi == mapBlockIndex.end()) {
-        nResult = 0;
-    } else {
-        CBlockIndex* pindex = (*mi).second;
-        if (!pindex || !chainActive.Contains(pindex)) {
-            nResult = 0;
-        } else {
-            nResult = (isConflicted() ? (-1) : 1) * (chainActive.Height() - pindex->nHeight + 1);
-        }
-    }
 
-    return nResult;
+    return (pwallet->GetLastBlockHeight() - m_confirm.block_height + 1) * (isConflicted() ? -1 : 1);
 }
 
 int CWalletTx::GetBlocksToMaturity() const

src/wallet/wallet.h

@@ -520,7 +520,13 @@ class CWalletTx
      *  0  : in memory pool, waiting to be included in a block
      * >=1 : this many blocks deep in the main chain
      */
-    int GetDepthInMainChain() const;
+    // TODO: Remove "NO_THREAD_SAFETY_ANALYSIS" and replace it with the correct
+    // annotation "EXCLUSIVE_LOCKS_REQUIRED(pwallet->cs_wallet)". The annotation
+    // "NO_THREAD_SAFETY_ANALYSIS" was temporarily added to avoid having to
+    // resolve the issue of member access into incomplete type CWallet. Note
+    // that we still have the runtime check "AssertLockHeld(pwallet->cs_wallet)"
+    // in place.
+    int GetDepthInMainChain() const NO_THREAD_SAFETY_ANALYSIS;
     bool IsInMainChainImmature() const;
     int GetBlocksToMaturity() const;