Merge pull request #5158

9ec75c5 Add a locking mechanism to IsInitialBlockDownload to ensure it never goes from false to true. (Ruben Dario Ponticelli)
a2d0fc6 Fix IsInitialBlockDownload which was broken by headers first. (Ruben Dario Ponticelli)

Author: laanwj

src/main.cpp

@@ -1199,15 +1199,14 @@ bool IsInitialBlockDownload()
     LOCK(cs_main);
     if (fImporting || fReindex || chainActive.Height() < Checkpoints::GetTotalBlocksEstimate())
         return true;
-    static int64_t nLastUpdate;
-    static CBlockIndex* pindexLastBest;
-    if (chainActive.Tip() != pindexLastBest)
-    {
-        pindexLastBest = chainActive.Tip();
-        nLastUpdate = GetTime();
-    }
-    return (GetTime() - nLastUpdate < 10 &&
-            chainActive.Tip()->GetBlockTime() < GetTime() - 24 * 60 * 60);
+    static bool lockIBDState = false;
+    if (lockIBDState)
+        return false;
+    bool state = (chainActive.Height() < pindexBestHeader->nHeight - 24 * 6 ||
+            pindexBestHeader->GetBlockTime() < GetTime() - 24 * 60 * 60);
+    if (!state)
+        lockIBDState = true;
+    return state;
 }
 
 bool fLargeWorkForkFound = false;