From f902b014972b8934a5cd0da773a4728f2da85ed7 Mon Sep 17 00:00:00 2001
From: Asdow <20314541+Asdow@users.noreply.github.com>
Date: Tue, 18 Nov 2025 22:45:37 +0200
Subject: [PATCH] Fix ubID underflow

Fixes illegal memory access if we tried to find previous merc and our currently selected one has ubID == 0
---
 Tactical/Overhead.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Tactical/Overhead.cpp b/Tactical/Overhead.cpp
index dd79d2ad..ca80c096 100644
--- a/Tactical/Overhead.cpp
+++ b/Tactical/Overhead.cpp
@@ -4896,7 +4896,13 @@ SoldierID FindPrevActiveAndAliveMerc( SOLDIERTYPE *pSoldier, BOOLEAN fGoodForLes
     SoldierID bLastTeamID = gTacticalStatus.Team[ pSoldier->bTeam ].bFirstID;
     SoldierID cnt = pSoldier->ubID - 1;
 
-    for ( ; cnt > bLastTeamID; --cnt )
+    // Guard against ubID underflow. We'll start searching for previous merc from the lastID in that case
+    if ( cnt >= NOBODY )
+    {
+        cnt = gTacticalStatus.Team[pSoldier->bTeam].bLastID;
+    }
+
+    for ( ; cnt >= bLastTeamID; --cnt )
     {
         pTeamSoldier = cnt;
         if ( fOnlyRegularMercs )