From 83be3826ff398e98f9926db77e67dc61cdbb6336 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=CE=B6eh=20Matt?= <5415177+ZehMatt@users.noreply.github.com>
Date: Wed, 16 Feb 2022 18:19:10 +0200
Subject: [PATCH] Fix #6618: Crash due to iterator invalidation

---
 apps/openmw/mwmechanics/aisequence.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/apps/openmw/mwmechanics/aisequence.cpp b/apps/openmw/mwmechanics/aisequence.cpp
index a1f2b5c3e3..0bece95088 100644
--- a/apps/openmw/mwmechanics/aisequence.cpp
+++ b/apps/openmw/mwmechanics/aisequence.cpp
@@ -309,12 +309,18 @@ void AiSequence::execute (const MWWorld::Ptr& actor, CharacterController& charac
     {
         if (package->execute(actor, characterController, mAiState, duration))
         {
-            // Put repeating noncombat AI packages on the end of the stack so they can be used again
+            const auto packageIdx = std::distance(mPackages.begin(), packageIt);
+
+            // Put repeating non-combat AI packages on the end of the stack so they can be used again
             if (isActualAiPackage(packageTypeId) && package->getRepeat())
             {
                 package->reset();
                 mPackages.push_back(package->clone());
             }
+
+            // Iterator may have been invalidated by push back ensure its correct.
+            packageIt = mPackages.begin() + packageIdx;
+
             // To account for the rare case where AiPackage::execute() queued another AI package
             // (e.g. AiPursue executing a dialogue script that uses startCombat)
             erase(packageIt);