From fa309e5b0e84c9287556234784d3abce1198c713 Mon Sep 17 00:00:00 2001
From: blackjok3r <blackjok3r@gmail.com>
Date: Tue, 2 Apr 2019 19:14:51 +0800
Subject: [PATCH] Add context flag to stop checking twice

---
 src/chain.h  |  5 ++++-
 src/main.cpp | 20 +++++++++++++-------
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/chain.h b/src/chain.h
index ee56c7662..d810ed4cb 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -102,6 +102,9 @@ enum BlockStatus: uint32_t {
     //! Scripts & signatures ok. Implies all parents are also at least SCRIPTS.
     BLOCK_VALID_SCRIPTS      =    5,
 
+    // flag to check if contextual check block has passed in Accept block, if it has not check at connect block. 
+    BLOCK_VALID_CONTEXT      =    6,
+    
     //! All validity bits.
     BLOCK_VALID_MASK         =   BLOCK_VALID_HEADER | BLOCK_VALID_TREE | BLOCK_VALID_TRANSACTIONS |
                                  BLOCK_VALID_CHAIN | BLOCK_VALID_SCRIPTS,
@@ -115,7 +118,7 @@ enum BlockStatus: uint32_t {
     BLOCK_FAILED_MASK        =   BLOCK_FAILED_VALID | BLOCK_FAILED_CHILD,
 
     BLOCK_ACTIVATES_UPGRADE  =   128, //! block activates a network upgrade
-    BLOCK_IN_TMPFILE = 256
+    BLOCK_IN_TMPFILE = 256 
 };
 
 //! Short-hand for the highest consensus validity we implement.
diff --git a/src/main.cpp b/src/main.cpp
index 20a963287..e8fe3810c 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3274,14 +3274,17 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin
         //fprintf(stderr,"checkblock failure in connectblock futureblock.%d\n",futureblock);
         return false;
     }
-    // check pindex->CONTEXT_VALIDATED flag
-    if ( fCheckPOW != 0 && !ContextualCheckBlock(block, state, pindex->pprev) ) // Activate Jan 15th, 2019
+    if ( fCheckPOW != 0 && (pindex->nStatus & BLOCK_VALID_CONTEXT) != BLOCK_VALID_CONTEXT ) // Activate Jan 15th, 2019
     {
-        fprintf(stderr,"ContextualCheckBlock failed ht.%d\n",(int32_t)pindex->GetHeight());
-        if ( pindex->nTime > 1547510400 )
-            return false;
-        fprintf(stderr,"grandfathered exception, until jan 15th 2019\n");
+        if ( !ContextualCheckBlock(block, state, pindex->pprev) )
+        {
+            fprintf(stderr,"ContextualCheckBlock failed ht.%d\n",(int32_t)pindex->GetHeight());
+            if ( pindex->nTime > 1547510400 )
+                return false;
+            fprintf(stderr,"grandfathered exception, until jan 15th 2019\n");
+        } else pindex->nStatus |= BLOCK_VALID_CONTEXT;
     }
+    
     // Do this here before the block is moved to the main block files.
     if ( ASSETCHAINS_NOTARY_PAY[0] != 0 && pindex->GetHeight() > 10 )
     {
@@ -5340,7 +5343,8 @@ bool AcceptBlock(int32_t *futureblockp,CBlock& block, CValidationState& state, C
 
     // See method docstring for why this is always disabled
     auto verifier = libzcash::ProofVerifier::Disabled();
-    if ((!CheckBlock(futureblockp,pindex->GetHeight(),pindex,block, state, verifier,0)) || !ContextualCheckBlock(block, state, pindex->pprev))
+    bool fContextualCheckBlock = ContextualCheckBlock(block, state, pindex->pprev);
+    if ( (!CheckBlock(futureblockp,pindex->GetHeight(),pindex,block, state, verifier,0)) || !fContextualCheckBlock )
     {
         static int32_t saplinght = -1;
         CBlockIndex *tmpptr;
@@ -5365,6 +5369,8 @@ bool AcceptBlock(int32_t *futureblockp,CBlock& block, CValidationState& state, C
             return false;
         }
     }
+    if ( fContextualCheckBlock )
+        pindex->nStatus |= BLOCK_VALID_CONTEXT;
 
     int nHeight = pindex->GetHeight();
     // Temp File fix. LABS has been using this for ages with no bad effects.