Core/Units: Partial implementation of SMSG_MOVE_SET_COLLISION_HGT - send proper character collision height on dismount.

Fixes #2642

NOTE: Still have to properly implement collision height calculation for mounting up.

src/server/game/Entities/Player/Player.h

@@ -2493,6 +2493,20 @@ class Player : public Unit, public GridObject<Player>
         void AddWhisperWhiteList(uint64 guid) { WhisperList.push_back(guid); }
         bool IsInWhisperWhiteList(uint64 guid);
 
+        //! Return collision height sent to client
+        //! we currently only send this on dismount
+        float GetCollisionHeight()
+        {
+            CreatureDisplayInfoEntry const* displayInfo = sCreatureDisplayInfoStore.LookupEntry(GetNativeDisplayId());
+            ASSERT(displayInfo);
+            CreatureModelDataEntry const* modelData = sCreatureModelDataStore.LookupEntry(displayInfo->ModelId);
+            ASSERT(modelData);
+
+            return modelData->CollisionHeight;
+
+            //! TODO: Need a proper calculation for collision height when mounted
+        }
+
     protected:
         // Gamemaster whisper whitelist
         WhisperListContainer WhisperList;

src/server/game/Entities/Unit/Unit.cpp

@@ -11946,6 +11946,15 @@ void Unit::Unmount()
     SetUInt32Value(UNIT_FIELD_MOUNTDISPLAYID, 0);
     RemoveFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_MOUNT);
 
+    if (Player* thisPlayer = ToPlayer())
+    {
+        WorldPacket data(SMSG_MOVE_SET_COLLISION_HGT, GetPackGUID().size() + 4 + 4);
+        data.append(GetPackGUID());
+        data << uint32(sWorld->GetGameTime());   // Packet counter
+        data << thisPlayer->GetCollisionHeight();
+        thisPlayer->GetSession()->SendPacket(&data);
+    }
+
     WorldPacket data(SMSG_DISMOUNT, 8);
     data.appendPackGUID(GetGUID());
     SendMessageToSet(&data, true);