Core/PetAI: apply some movement related corrections

Unit::StopMoving() is evil, and so is MotionMaster::Clear()

the first can really mess up existing movement generators
the second can interrupt "controlled" movements... can do it literally mid-air

(cherry picked from commit 74678b247e04728562e78f6a624577964020a7f0)

2 files changed, 23 insertions, 10 deletions

diff --git a/src/server/game/AI/CoreAI/PetAI.cpp b/src/server/game/AI/CoreAI/PetAI.cpp
index e92db6063f4..006fad0acf3 100644
--- a/src/server/game/AI/CoreAI/PetAI.cpp
+++ b/src/server/game/AI/CoreAI/PetAI.cpp
@@ -447,7 +447,10 @@ void PetAI::HandleReturnMovement()
             me->GetCharmInfo()->GetStayPosition(x, y, z);
             ClearCharmInfoFlags();
             me->GetCharmInfo()->SetIsReturning(true);
-            me->GetMotionMaster()->Clear();
+
+            if (me->HasUnitState(UNIT_STATE_CHASE))
+                me->GetMotionMaster()->Remove(CHASE_MOTION_TYPE);
+
             me->GetMotionMaster()->MovePoint(me->GetGUID().GetCounter(), x, y, z);
         }
     }
@@ -457,7 +460,10 @@ void PetAI::HandleReturnMovement()
         {
             ClearCharmInfoFlags();
             me->GetCharmInfo()->SetIsReturning(true);
-            me->GetMotionMaster()->Clear();
+
+            if (me->HasUnitState(UNIT_STATE_CHASE))
+                me->GetMotionMaster()->Remove(CHASE_MOTION_TYPE);
+
             me->GetMotionMaster()->MoveFollow(me->GetCharmerOrOwner(), PET_FOLLOW_DIST, me->GetFollowAngle());
         }
     }
@@ -481,29 +487,35 @@ void PetAI::DoAttack(Unit* target, bool chase)
             bool oldCmdAttack = me->GetCharmInfo()->IsCommandAttack(); // This needs to be reset after other flags are cleared
             ClearCharmInfoFlags();
             me->GetCharmInfo()->SetIsCommandAttack(oldCmdAttack); // For passive pets commanded to attack so they will use spells
-            me->GetMotionMaster()->Clear();
-            me->GetMotionMaster()->MoveChase(target, me->GetPetChaseDistance(), (float)M_PI);
+
+            if (me->HasUnitState(UNIT_STATE_FOLLOW))
+                me->GetMotionMaster()->Remove(FOLLOW_MOTION_TYPE);
+
+            me->GetMotionMaster()->MoveChase(target, me->GetPetChaseDistance(), float(M_PI));
         }
         else // (Stay && ((Aggressive || Defensive) && In Melee Range)))
         {
             ClearCharmInfoFlags();
             me->GetCharmInfo()->SetIsAtStay(true);
-            me->GetMotionMaster()->Clear();
+
+            if (me->HasUnitState(UNIT_STATE_FOLLOW))
+                me->GetMotionMaster()->Remove(FOLLOW_MOTION_TYPE);
+
             me->GetMotionMaster()->MoveIdle();
         }
     }
 }
 
-void PetAI::MovementInform(uint32 moveType, uint32 data)
+void PetAI::MovementInform(uint32 type, uint32 id)
 {
     // Receives notification when pet reaches stay or follow owner
-    switch (moveType)
+    switch (type)
     {
         case POINT_MOTION_TYPE:
         {
             // Pet is returning to where stay was clicked. data should be
             // pet's GUIDLow since we set that as the waypoint ID
-            if (data == me->GetGUID().GetCounter() && me->GetCharmInfo()->IsReturning())
+            if (id == me->GetGUID().GetCounter() && me->GetCharmInfo()->IsReturning())
             {
                 ClearCharmInfoFlags();
                 me->GetCharmInfo()->SetIsAtStay(true);
@@ -516,7 +528,7 @@ void PetAI::MovementInform(uint32 moveType, uint32 data)
         {
             // If data is owner's GUIDLow then we've reached follow point,
             // otherwise we're probably chasing a creature
-            if (me->GetCharmerOrOwner() && me->GetCharmInfo() && data == me->GetCharmerOrOwner()->GetGUID().GetCounter() && me->GetCharmInfo()->IsReturning())
+            if (me->GetCharmerOrOwner() && me->GetCharmInfo() && id == me->GetCharmerOrOwner()->GetGUID().GetCounter() && me->GetCharmInfo()->IsReturning())
             {
                 ClearCharmInfoFlags();
                 me->GetCharmInfo()->SetIsFollowing(true);
diff --git a/src/server/game/AI/CoreAI/PetAI.h b/src/server/game/AI/CoreAI/PetAI.h
index 5df11ad8282..4ce30b1f93f 100644
--- a/src/server/game/AI/CoreAI/PetAI.h
+++ b/src/server/game/AI/CoreAI/PetAI.h
@@ -39,7 +39,7 @@ class TC_GAME_API PetAI : public CreatureAI
         void AttackStart(Unit* target) override;
         // always start attacking if possible
         void _AttackStart(Unit* target);
-        void MovementInform(uint32 moveType, uint32 data) override;
+        void MovementInform(uint32 type, uint32 id) override;
         void OwnerAttackedBy(Unit* attacker) override;
         void OwnerAttacked(Unit* target) override;
         void DamageTaken(Unit* attacker, uint32& /*damage*/) override { AttackStart(attacker); }
@@ -67,4 +67,5 @@ class TC_GAME_API PetAI : public CreatureAI
         GuidSet _allySet;
         uint32 _updateAlliesTimer;
 };
+
 #endif