From 780bc3f1d756f98a897d16bcad5061c8123a281e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gyuhwan=20Park=E2=98=85?= <unstabler@unstabler.pl>
Date: Tue, 5 Sep 2023 12:11:54 +0900
Subject: [PATCH] fix: prevent division by zero when rectSize is
 RECT_SIZE_BYPASS_CREATE (0)

---
 XrdpUlalacaPrivate.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/XrdpUlalacaPrivate.cpp b/XrdpUlalacaPrivate.cpp
index 97f7db7..70dd340 100644
--- a/XrdpUlalacaPrivate.cpp
+++ b/XrdpUlalacaPrivate.cpp
@@ -98,13 +98,15 @@ std::shared_ptr<std::vector<ULIPCRect>> XrdpUlalacaPrivate::createCopyRects(
     int rectSize
 ) const {
     auto blocks = std::make_shared<std::vector<ULIPCRect>>();
-    blocks->reserve((_sessionSize.width * _sessionSize.height) / (rectSize * rectSize));
 
     if (rectSize == RECT_SIZE_BYPASS_CREATE) {
+        blocks->reserve(dirtyRects.size());
         std::copy(dirtyRects.begin(), dirtyRects.end(), std::back_insert_iterator(*blocks));
         return std::move(blocks);
     }
 
+    blocks->reserve((_sessionSize.width * _sessionSize.height) / (rectSize * rectSize));
+
     int mapWidth  = std::ceil((float) _sessionSize.width / (float) rectSize);
     int mapHeight = std::ceil((float) _sessionSize.height / (float) rectSize);
     int mapSize = mapWidth * mapHeight;