Merge bitcoin/bitcoin#29647: Avoid divide-by-zero in header sync logs when NodeClock is behind

fa4d98b3c8e63f20c6f366fc9382039ba52614a4 Avoid divide-by-zero in header sync logs when NodeClock is behind (MarcoFalke)
fa58550317c633c411009c1cc8fb692e3baf97e8 refactor: Modernize header sync logs (MarcoFalke)

Pull request description:

  The log may be confusing, when the NodeClock is behind the current header tip.

  Fix it, by assuming the NodeClock is never behind the current header tip.

ACKs for top commit:
  sipa:
    utACK fa4d98b3c8e63f20c6f366fc9382039ba52614a4
  sr-gi:
    tACK [fa4d98b](https://github.com/bitcoin/bitcoin/pull/29647/commits/fa4d98b3c8e63f20c6f366fc9382039ba52614a4)
  achow101:
    ACK fa4d98b3c8e63f20c6f366fc9382039ba52614a4
  tdb3:
    ACK fa4d98b3c8e63f20c6f366fc9382039ba52614a4

Tree-SHA512: 3c5aee4030af387695918c5238012c972ebf850b52e956b5f74590cd7fd4eff0b3e593d411e3eb2a0bb12294af8dc6fbe320f90e4c261399b65a404ff3c3cbd9

1 files changed, 6 insertions, 4 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index b6d0c38f39..a8c98ae9ba 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -4234,9 +4234,10 @@ bool ChainstateManager::ProcessNewBlockHeaders(const std::vector<CBlockHeader>&
     if (NotifyHeaderTip(*this)) {
         if (IsInitialBlockDownload() && ppindex && *ppindex) {
             const CBlockIndex& last_accepted{**ppindex};
-            const int64_t blocks_left{(GetTime() - last_accepted.GetBlockTime()) / GetConsensus().nPowTargetSpacing};
+            int64_t blocks_left{(NodeClock::now() - last_accepted.Time()) / GetConsensus().PowTargetSpacing()};
+            blocks_left = std::max<int64_t>(0, blocks_left);
             const double progress{100.0 * last_accepted.nHeight / (last_accepted.nHeight + blocks_left)};
-            LogPrintf("Synchronizing blockheaders, height: %d (~%.2f%%)\n", last_accepted.nHeight, progress);
+            LogInfo("Synchronizing blockheaders, height: %d (~%.2f%%)\n", last_accepted.nHeight, progress);
         }
     }
     return true;
@@ -4260,9 +4261,10 @@ void ChainstateManager::ReportHeadersPresync(const arith_uint256& work, int64_t
     bool initial_download = IsInitialBlockDownload();
     GetNotifications().headerTip(GetSynchronizationState(initial_download), height, timestamp, /*presync=*/true);
     if (initial_download) {
-        const int64_t blocks_left{(GetTime() - timestamp) / GetConsensus().nPowTargetSpacing};
+        int64_t blocks_left{(NodeClock::now() - NodeSeconds{std::chrono::seconds{timestamp}}) / GetConsensus().PowTargetSpacing()};
+        blocks_left = std::max<int64_t>(0, blocks_left);
         const double progress{100.0 * height / (height + blocks_left)};
-        LogPrintf("Pre-synchronizing blockheaders, height: %d (~%.2f%%)\n", height, progress);
+        LogInfo("Pre-synchronizing blockheaders, height: %d (~%.2f%%)\n", height, progress);
     }
 }