From 77db91ae8cb861c09b3aa5017f8561bed2df3473 Mon Sep 17 00:00:00 2001
From: Yujon Pradhananga <139200034+Yujonpradhananga@users.noreply.github.com>
Date: Mon, 2 Mar 2026 00:04:02 +0545
Subject: [PATCH] layout/scrolling: fix size_t underflow in idxForHeight
 (#13465)

---
 src/layout/algorithm/tiled/scrolling/ScrollingAlgorithm.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/layout/algorithm/tiled/scrolling/ScrollingAlgorithm.cpp b/src/layout/algorithm/tiled/scrolling/ScrollingAlgorithm.cpp
index d9382c725..c7fe60787 100644
--- a/src/layout/algorithm/tiled/scrolling/ScrollingAlgorithm.cpp
+++ b/src/layout/algorithm/tiled/scrolling/ScrollingAlgorithm.cpp
@@ -190,10 +190,12 @@ size_t SColumnData::idx(SP<ITarget> t) {
 }
 
 size_t SColumnData::idxForHeight(float y) {
+    if (targetDatas.empty())
+        return 0;
     for (size_t i = 0; i < targetDatas.size(); ++i) {
         if (targetDatas[i]->target->position().y < y)
             continue;
-        return i - 1;
+        return i == 0 ? 0 : i - 1;
     }
     return targetDatas.size() - 1;
 }