From b882d194ba7748b5848b8ca9319313184a4a697f Mon Sep 17 00:00:00 2001
From: Daniel Liu <139250065@qq.com>
Date: Wed, 8 Oct 2025 13:21:33 +0800
Subject: [PATCH] engine_v2: fix potential modulo by zero, close XFN-17 (#1615)

---
 consensus/XDPoS/engines/engine_v2/utils.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/consensus/XDPoS/engines/engine_v2/utils.go b/consensus/XDPoS/engines/engine_v2/utils.go
index 0b6d2401c6..2b957282cd 100644
--- a/consensus/XDPoS/engines/engine_v2/utils.go
+++ b/consensus/XDPoS/engines/engine_v2/utils.go
@@ -217,6 +217,9 @@ func (x *XDPoS_v2) CalculateMissingRounds(chain consensus.ChainReader, header *t
 		return nil, err
 	}
 	masternodes := switchInfo.Masternodes
+	if len(masternodes) == 0 {
+		return nil, fmt.Errorf("masternodes is empty in CalculateMissingRounds, number = %v, hash %#x", header.Number, header.Hash())
+	}
 
 	// Loop through from the epoch switch block to the current "header" block
 	nextHeader := header