Core/SmartAI: Delay SMART_ACTION_FORCE_DESPAWN by at least one world tick

- Restore old despawn behavior of SmartAI despawning (without reintroducing the run time logs caused by IsSmart)
- Some SAIs relied on this to function (for example #1249)

Partial reverts commit 4fc4c81e8989febd7e650d749af358548e264e2c

(cherrypicked from aa7ef797d6c362710a38c12e31db4b8f3b2963e4)

1 files changed, 18 insertions, 5 deletions

diff --git a/src/server/game/AI/SmartScripts/SmartScript.cpp b/src/server/game/AI/SmartScripts/SmartScript.cpp
index a43d592d745..f5026728012 100644
--- a/src/server/game/AI/SmartScripts/SmartScript.cpp
+++ b/src/server/game/AI/SmartScripts/SmartScript.cpp
@@ -1230,11 +1230,24 @@ void SmartScript::ProcessAction(SmartScriptHolder& e, Unit* unit, uint32 var0, u
             if (!targets)
                 break;
 
-            for (ObjectList::const_iterator itr = targets->begin(); itr != targets->end(); ++itr)
-                if (Creature* target = (*itr)->ToCreature())
-                    target->DespawnOrUnsummon(e.action.forceDespawn.delay, Seconds(e.action.forceDespawn.respawn));
-                else if (GameObject* goTarget = (*itr)->ToGameObject())
-                    goTarget->SetRespawnTime(e.action.forceDespawn.delay + 1);
+            // there should be at least a world update tick before despawn, to avoid breaking linked actions
+            int32 const respawnDelay = std::max<int32>(e.action.forceDespawn.delay, 1);
+
+            for (WorldObject* target : *targets)
+            {
+                if (Creature* creatureTarget = target->ToCreature())
+                {
+                    if (SmartAI* smartAI = CAST_AI(SmartAI, creatureTarget->AI()))
+                    {
+                        smartAI->SetDespawnTime(respawnDelay);
+                        smartAI->StartDespawn();
+                    }
+                    else
+                        creatureTarget->DespawnOrUnsummon(respawnDelay);
+                }
+                else if (GameObject* goTarget = target->ToGameObject())
+                    goTarget->SetRespawnTime(respawnDelay);
+            }
 
             delete targets;
             break;