From a413bf7aad25a67c515ac44db718514cd0dc679b Mon Sep 17 00:00:00 2001
From: Hisayori Noda <nodchip@gmail.com>
Date: Mon, 24 Jun 2019 23:17:46 +0900
Subject: [PATCH] Added hack to avoid crash during machine learning.

---
 src/learn/learner.cpp | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/learn/learner.cpp b/src/learn/learner.cpp
index 34ea38c6..a0a3833a 100644
--- a/src/learn/learner.cpp
+++ b/src/learn/learner.cpp
@@ -2056,13 +2056,17 @@ void LearnerThink::thread_worker(size_t thread_id)
 		};
 
 		StateInfo state[MAX_PLY]; // qsearchのPVがそんなに長くなることはありえない。
+		bool illegal_move = false;
 		for (auto m : pv)
 		{
 			// 非合法手はやってこないはずなのだが。
+			// An illegal move sometimes comes here...
 			if (!pos.pseudo_legal(m) || !pos.legal(m))
 			{
-				cout << pos << m << endl;
-				assert(false);
+				//cout << pos << m << endl;
+				//assert(false);
+				illegal_move = true;
+				break;
 			}
 
 			// 各PV上のnodeでも勾配を加算する場合の処理。
@@ -2076,6 +2080,11 @@ void LearnerThink::thread_worker(size_t thread_id)
 			Eval::evaluate_with_no_return(pos);
 		}
 
+		if (illegal_move) {
+			sync_cout << "An illical move was detected... Excluded the position from the learning data..." << sync_endl;
+			continue;
+		}
+
 		// PVの終端局面に達したので、ここで勾配を加算する。
 		pos_add_grad();