X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.cpp;h=b7bead9ff0c867627105cb0eb8ee9ffa328c733e;hp=71b9ce0c091412e6424791c1e38bd4553fc04f7c;hb=db4cd89cb889446fb349d0d93640b640b1b9a8a1;hpb=8ceef922662c75c33d105d99732475c125b01081

diff --git a/src/thread.cpp b/src/thread.cpp
index 71b9ce0c..b7bead9f 100644
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -366,12 +366,16 @@ void ThreadPool::start_thinking(const Position& pos, const LimitsType& limits,
   Signals.stopOnPonderhit = Signals.firstRootMove = false;
   Signals.stop = Signals.failedLowAtRoot = false;
 
+  RootMoves.clear();
   RootPos = pos;
   Limits = limits;
-  SetupStates = states; // Ownership transfer here
-  RootMoves.clear();
+  if (states.get()) // If we don't set a new position, preserve current state
+  {
+      SetupStates = states; // Ownership transfer here
+      assert(!states.get());
+  }
 
-  for (MoveList<LEGAL> it(pos); !it.end(); ++it)
+  for (MoveList<LEGAL> it(pos); *it; ++it)
       if (   searchMoves.empty()
           || std::count(searchMoves.begin(), searchMoves.end(), *it))
           RootMoves.push_back(RootMove(*it));