From 520ae07ad5a1d519820f3f59b64152527cd4dbf7 Mon Sep 17 00:00:00 2001
From: jpirnay <jens@pirnay.com>
Date: Sat, 7 Mar 2026 10:20:11 +0100
Subject: [PATCH] Pick up assert recommendation

---
 lib/Epub/Epub/hyphenation/Hyphenator.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/Epub/Epub/hyphenation/Hyphenator.cpp b/lib/Epub/Epub/hyphenation/Hyphenator.cpp
index b0f3eec7..c0fdb85e 100644
--- a/lib/Epub/Epub/hyphenation/Hyphenator.cpp
+++ b/lib/Epub/Epub/hyphenation/Hyphenator.cpp
@@ -1,6 +1,7 @@
 #include "Hyphenator.h"
 
 #include <algorithm>
+#include <cassert>
 #include <vector>
 
 #include "HyphenationCommon.h"
@@ -85,6 +86,8 @@ void appendSegmentPatternBreaks(const std::vector<CodepointInfo>& cps, const Lan
       }
 
       for (const size_t idx : segIndexes) {
+        assert(idx > 0 && idx < segment.size());
+        if (idx == 0 || idx >= segment.size()) continue;
         const size_t cpIdx = segStart + idx;
         if (cpIdx < cps.size()) {
           outBreaks.push_back({cps[cpIdx].byteOffset, true});