Add two extra model fields to creature_template

(based on cmangos/mangos-classic@cd32eab)

Signed-off-by: stfx <stfx@hotmail.de>

(based on cmangos/mangos-wotlk@c353700)

Signed-off-by: stfx <stfx@hotmail.de>

src/game/Creature.cpp

@@ -454,8 +454,10 @@ uint32 Creature::ChooseDisplayId(const CreatureInfo* cinfo, const CreatureData*
     // if mod2                          use mod2 unless mod2 has modelid_alt_model (then both by 50%-chance)
     // if mod1                          use mod1
 
-    // model selected here may be replaced with other_gender using own function
+    // The follow decision tree needs to be updated if MAX_CREATURE_MODEL is changed.
+    static_assert(MAX_CREATURE_MODEL == 4, "Need to update model selection code for new or removed model fields");
 
+    // model selected here may be replaced with other_gender using own function
     if (cinfo->ModelId[3] && cinfo->ModelId[2] && cinfo->ModelId[1] && cinfo->ModelId[0])
     {
         display_id = cinfo->ModelId[urand(0, 3)];
@@ -1129,6 +1131,9 @@ void Creature::SaveToDB(uint32 mapid, uint8 spawnMask, uint32 phaseMask)
     CreatureInfo const* cinfo = GetCreatureInfo();
     if (cinfo)
     {
+        // The following if-else assumes that there are 4 model fields and needs updating if this is changed.
+        static_assert(MAX_CREATURE_MODEL == 4, "Need to update custom model check for new/removed model fields.");
+
         if (displayId != cinfo->ModelId[0] && displayId != cinfo->ModelId[1] &&
                 displayId != cinfo->ModelId[2] && displayId != cinfo->ModelId[3])
         {