Remove remaining chainActive references from CWallet

This commit does not change behavior.

Co-authored-by: Ben Woosley <ben.woosley@gmail.com>

src/interfaces/chain.cpp

@@ -60,6 +60,11 @@ class LockImpl : public Chain::Lock
         assert(block != nullptr);
         return block->GetMedianTimePast();
     }
+    bool haveBlockOnDisk(int height) override
+    {
+        CBlockIndex* block = ::chainActive[height];
+        return block && ((block->nStatus & BLOCK_HAVE_DATA) != 0) && block->nTx > 0;
+    }
     Optional<int> findFirstBlockWithTime(int64_t time, uint256* hash) override
     {
         CBlockIndex* block = ::chainActive.FindEarliestAtLeast(time);
@@ -112,6 +117,21 @@ class LockImpl : public Chain::Lock
         }
         return nullopt;
     }
+    bool isPotentialTip(const uint256& hash) override
+    {
+        if (::chainActive.Tip()->GetBlockHash() == hash) return true;
+        CBlockIndex* block = LookupBlockIndex(hash);
+        return block && block->GetAncestor(::chainActive.Height()) == ::chainActive.Tip();
+    }
+    CBlockLocator getLocator() override { return ::chainActive.GetLocator(); }
+    Optional<int> findLocatorFork(const CBlockLocator& locator) override
+    {
+        LockAnnotation lock(::cs_main);
+        if (CBlockIndex* fork = FindForkInGlobalIndex(::chainActive, locator)) {
+            return fork->nHeight;
+        }
+        return nullopt;
+    }
 };
 
 class LockingStateImpl : public LockImpl, public UniqueLock<CCriticalSection>

src/interfaces/chain.h

@@ -15,6 +15,7 @@
 class CBlock;
 class CScheduler;
 class uint256;
+struct CBlockLocator;
 
 namespace interfaces {
 
@@ -58,6 +59,10 @@ public:
         //! will abort.
         virtual int64_t getBlockMedianTimePast(int height) = 0;
 
+        //! Check that the block is available on disk (i.e. has not been
+        //! pruned), and contains transactions.
+        virtual bool haveBlockOnDisk(int height) = 0;
+
         //! Return height of the first block in the chain with timestamp equal
         //! or greater than the given time, or nullopt if there is no block with
         //! a high enough timestamp. Also return the block hash as an optional
@@ -84,6 +89,19 @@ public:
         //! parameter (to avoid the cost of a second hash lookup in case this
         //! information is desired).
         virtual Optional<int> findFork(const uint256& hash, Optional<int>* height) = 0;
+
+        //! Return true if block hash points to the current chain tip, or to a
+        //! possible descendant of the current chain tip that isn't currently
+        //! connected.
+        virtual bool isPotentialTip(const uint256& hash) = 0;
+
+        //! Get locator for the current chain tip.
+        virtual CBlockLocator getLocator() = 0;
+
+        //! Return height of the latest block common to locator and chain, which
+        //! is guaranteed to be an ancestor of the block used to create the
+        //! locator.
+        virtual Optional<int> findLocatorFork(const CBlockLocator& locator) = 0;
     };
 
     //! Return Lock interface. Chain is locked when this is called, and