Core/Movement: implement and use new remove method in MotionMaster

All erases within MotionMaster are now done by itr.
Previous impl used value erase which uses the custom comparator which does not identify elements uniquely --> wrong values were deleted

ref #23187#discussion_r275791179

(cherry picked from commit 11de6b5f866e087307a719b931be8c51b984c54e)

2 files changed, 17 insertions, 28 deletions

diff --git a/src/server/game/Movement/MotionMaster.cpp b/src/server/game/Movement/MotionMaster.cpp
index 2114b94f6a4..9f36af744b1 100644
--- a/src/server/game/Movement/MotionMaster.cpp
+++ b/src/server/game/Movement/MotionMaster.cpp
@@ -363,12 +363,7 @@ void MotionMaster::Remove(MovementGenerator* movement, MovementSlot slot/* = MOT
             {
                 auto itr = _generators.find(movement);
                 if (itr != _generators.end())
-                {
-                    MovementGenerator* pointer = *itr;
-                    bool const top = GetCurrentMovementGenerator() == pointer;
-                    _generators.erase(pointer);
-                    Delete(pointer, top, false);
-                }
+                    Remove(itr, GetCurrentMovementGenerator() == *itr, false);
             }
             break;
         default:
@@ -409,12 +404,7 @@ void MotionMaster::Remove(MovementGeneratorType type, MovementSlot slot/* = MOTI
                 });
 
                 if (itr != _generators.end())
-                {
-                    MovementGenerator* pointer = *itr;
-                    bool const top = GetCurrentMovementGenerator() == pointer;
-                    _generators.erase(pointer);
-                    Delete(pointer, top, false);
-                }
+                    Remove(itr, GetCurrentMovementGenerator() == *itr, false);
             }
             break;
         default:
@@ -1079,13 +1069,18 @@ void MotionMaster::LaunchMoveSpline(Movement::MoveSplineInit&& init, uint32 id/*
 
 /******************** Private methods ********************/
 
-void MotionMaster::Pop(bool active, bool movementInform)
+void MotionMaster::Remove(MotionMasterContainer::iterator iterator, bool active, bool movementInform)
 {
-    MovementGenerator* pointer = *_generators.begin();
-    _generators.erase(pointer);
+    MovementGenerator* pointer = *iterator;
+    _generators.erase(iterator);
     Delete(pointer, active, movementInform);
 }
 
+void MotionMaster::Pop(bool active, bool movementInform)
+{
+    Remove(_generators.begin(), active, movementInform);
+}
+
 void MotionMaster::DirectInitialize()
 {
     // Clear ALL movement generators (including default)
@@ -1180,14 +1175,11 @@ void MotionMaster::DirectAdd(MovementGenerator* movement, MovementSlot slot/* =
             {
                 if (movement->Priority >= (*_generators.begin())->Priority)
                 {
-                    MovementGenerator* pointer = *_generators.begin();
-                    if (movement->Priority == pointer->Priority)
-                    {
-                        _generators.erase(pointer);
-                        Delete(pointer, true, false);
-                    }
+                    auto itr = _generators.begin();
+                    if (movement->Priority == (*itr)->Priority)
+                        Remove(itr, true, false);
                     else
-                        pointer->Deactivate(_owner);
+                        (*itr)->Deactivate(_owner);
                 }
                 else
                 {
@@ -1197,11 +1189,7 @@ void MotionMaster::DirectAdd(MovementGenerator* movement, MovementSlot slot/* =
                     });
 
                     if (itr != _generators.end())
-                    {
-                        MovementGenerator* pointer = *itr;
-                        _generators.erase(pointer);
-                        Delete(pointer, false, false);
-                    }
+                        Remove(itr, false, false);
                 }
             }
             else
diff --git a/src/server/game/Movement/MotionMaster.h b/src/server/game/Movement/MotionMaster.h
index 8ed38897ea5..afe61a6dd55 100644
--- a/src/server/game/Movement/MotionMaster.h
+++ b/src/server/game/Movement/MotionMaster.h
@@ -122,7 +122,7 @@ class TC_GAME_API MotionMaster
         // Removes first found movement
         // NOTE: MOTION_SLOT_DEFAULT will be autofilled with IDLE_MOTION_TYPE
         void Remove(MovementGeneratorType type, MovementSlot slot = MOTION_SLOT_ACTIVE);
-        // NOTE: NOTE: MOTION_SLOT_DEFAULT wont be affected
+        // NOTE: MOTION_SLOT_DEFAULT wont be affected
         void Clear();
         // Removes all movements for the given MovementSlot
         // NOTE: MOTION_SLOT_DEFAULT will be autofilled with IDLE_MOTION_TYPE
@@ -189,6 +189,7 @@ class TC_GAME_API MotionMaster
         bool HasFlag(uint8 const flag) const { return (_flags & flag) != 0; }
         void RemoveFlag(uint8 const flag) { _flags &= ~flag; }
 
+        void Remove(MotionMasterContainer::iterator iterator, bool active, bool movementInform);
         void Pop(bool active, bool movementInform);
         void DirectInitialize();
         void DirectClear();