From 0e7fabc8ae0127a994aaece31e3c69a510cef527 Mon Sep 17 00:00:00 2001
From: Niklas Fiekas <niklas.fiekas@backscattering.de>
Date: Fri, 27 Sep 2024 17:37:16 +0200
Subject: [PATCH] Test reading PGN with UTF-8 BOM

---
 data/pgn/utf8-bom.pgn | 26 ++++++++++++++++++++++++++
 test.py               | 12 ++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 data/pgn/utf8-bom.pgn

diff --git a/data/pgn/utf8-bom.pgn b/data/pgn/utf8-bom.pgn
new file mode 100644
index 000000000..665e7775a
--- /dev/null
+++ b/data/pgn/utf8-bom.pgn
@@ -0,0 +1,26 @@
+[Event "A"]
+[Site "?"]
+[Date "2024.04.25"]
+[Round "?"]
+[White "White vs 1...c5"]
+[Black "?"]
+[Result "*"]
+[ECO "A00"]
+[PlyCount "0"]
+[SourceVersionDate "2024.04.25"]
+
+ *
+
+[Event "B"]
+[Site "?"]
+[Date "2024.04.25"]
+[Round "?"]
+[White "White vs 1...c5"]
+[Black "?"]
+[Result "*"]
+[ECO "A00"]
+[PlyCount "0"]
+[SourceVersionDate "2024.04.25"]
+
+ *
+
diff --git a/test.py b/test.py
index 438628b98..6102eabdb 100755
--- a/test.py
+++ b/test.py
@@ -2947,6 +2947,18 @@ def end_variation(self):
         game = chess.pgn.read_game(io.StringIO(pgn)).accept(BlackVariationsOnly())
         self.assertEqual(game.accept(chess.pgn.StringExporter(headers=False)), expected_pgn)
 
+    def test_utf8_bom(self):
+        not_utf8_sig = "utf-8"
+        with open("data/pgn/utf8-bom.pgn", encoding=not_utf8_sig) as pgn:
+            game = chess.pgn.read_game(pgn)
+            self.assertEqual(game.headers["Event"], "A")
+
+            game = chess.pgn.read_game(pgn)
+            self.assertEqual(game.headers["Event"], "B")
+
+            game = chess.pgn.read_game(pgn)
+            self.assertEqual(game, None)
+
 
 @unittest.skipIf(sys.platform == "win32" and (3, 8, 0) <= sys.version_info < (3, 8, 1), "https://bugs.python.org/issue34679")
 class EngineTestCase(unittest.TestCase):