Merge pull request #5520

bdb6a71 IsNull doesn't change CBlockLocator, add const hint (Pavel Janík)
1b37333 Remove no longer needed declaration of CBlockLocator (Pavel Janík)

src/db.h

@@ -23,8 +23,6 @@
 class CDiskBlockIndex;
 class COutPoint;
 
-struct CBlockLocator;
-
 extern unsigned int nWalletDBUpdated;
 
 void ThreadFlushWalletDB(const std::string& strWalletFile);

src/primitives/block.h

@@ -162,7 +162,7 @@ struct CBlockLocator
         vHave.clear();
     }
 
-    bool IsNull()
+    bool IsNull() const
     {
         return vHave.empty();
     }