Fix illegal move in PV when mate in next move.

petur · Nov 12, 2022 · 0334bb8 · 0334bb8
1 parent a7c334f
commit 0334bb8
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diff --git a/seawall.cc b/seawall.cc
@@ -1681,7 +1681,11 @@ std::pair<int, Move> Search::search(bool pv, int ply, int depth, int alpha, int
     }
 
     if (move_count == 0)
+    {
+        if (pv)
+            pv_lines[ply].length = 0;
         return {checkers ? -SCORE_MATE + ply : 0, NO_MOVE};
+    }
     if (ply > 0 && position.halfmove_clock >= 100)
         return {0, NULL_MOVE};
 

diff --git a/test.sh b/test.sh
@@ -54,5 +54,7 @@ echo 'position fen 6Q1/8/8/8/8/7K/8/7k b - - 0 1'
 echo 'go depth 1'
 echo 'position fen 7Q/8/8/8/8/8/8/5K1k b - - 0 1'
 echo 'go depth 1'
+echo 'position fen 6k1/5p1p/2pB4/8/1ppPp3/2n1P2p/p1PK1q2/Q7 w - - 0 49 moves d2c1 f2f1 c1d2 c3b1'
+echo 'go wtime 33 winc 0 btime 31 binc 0 movestogo 32'
 echo 'quit'
 ) | ./seawall