Fix Vanilla damage adjustment scaling

sql/world/base/dungeon_karazhan.sql

@@ -0,0 +1,2 @@
+# Restore Enchanting formula drops to their pre-3.1 rates
+UPDATE `creature_loot_template` SET `Chance` = 5 WHERE `Item` IN (22559, 22561, 22545, 22560);

src/IndividualProgression.cpp

@@ -143,6 +143,12 @@ void IndividualProgression::AdjustStats(Player* player, float computedAdjustment
     player->CastCustomSpell(player, ABSORB_SPELL, &bp1, nullptr, nullptr, false);
 }
 
+float IndividualProgression::ComputeVanillaAdjustment(Player *player, float configAdjustmentValue)
+{
+    float adjustmentApplyPercent = (player->getLevel() - 10.0f) / 50.0f;
+    return player->getLevel() > 10 ? (1.0f - (configAdjustmentValue * adjustmentApplyPercent)) : 1;
+}
+
 /**
  * Gets the highest progression level achieved by an account
  * Note that this method makes a direct, non-sync DB call and should be used sparingly

src/IndividualProgression.h

@@ -44,6 +44,7 @@ enum BuffSpells
     ABSORB_SPELL = 89505,
     RANGED_HASTE_SPELL = 89507,
     SPELL_RUNE_TAP = 48982,
+    SPELL_LIFE_STEAL = 20004,
     IPP_PHASE = 89509
 };
 
@@ -161,6 +162,7 @@ public:
     void checkKillProgression(Player* player, Creature* killed);
     static void LoadCustomProgressionEntries(const std::string& customProgressionString);
     static void AdjustStats(Player* player, float computedAdjustment, float computedHealingAdjustment);
+    static float ComputeVanillaAdjustment(Player* player, float configAdjustmentValue);
     static uint8 GetAccountProgression(uint32 accountId);
 };
 

src/IndividualProgressionPlayer.cpp

@@ -475,7 +475,13 @@ public:
     void ModifyHealReceived(Unit* /*target*/, Unit *healer, uint32 &heal, SpellInfo const *spellInfo) override
     {
         // Skip potions, bandages, percentage based heals like Rune Tap, etc.
-        if (!sIndividualProgression->enabled || spellInfo->HasAttribute(SPELL_ATTR0_NO_IMMUNITIES) || spellInfo->Mechanic == MECHANIC_BANDAGE || spellInfo->Id == SPELL_RUNE_TAP)
+        if (!sIndividualProgression->enabled || spellInfo->HasAttribute(SPELL_ATTR0_NO_IMMUNITIES) || spellInfo->Mechanic == MECHANIC_BANDAGE)
+        {
+            return;
+        }
+
+        // Skip percentage based heals or spells already nerfed by damage reduction
+        if (spellInfo->Id == SPELL_RUNE_TAP || spellInfo->Id == SPELL_LIFE_STEAL)
         {
             return;
         }
@@ -493,7 +499,7 @@ public:
         float gearAdjustment = computeTotalGearTuning(player);
         if (!sIndividualProgression->hasPassedProgression(player, PROGRESSION_NAXX40))
         {
-            heal *= (sIndividualProgression->vanillaHealingAdjustment - gearAdjustment);
+            heal *= (sIndividualProgression->ComputeVanillaAdjustment(player, sIndividualProgression->vanillaHealingAdjustment) - gearAdjustment);
         }
         else if (!sIndividualProgression->hasPassedProgression(player, PROGRESSION_TBC_TIER_5))
         {
@@ -519,7 +525,7 @@ public:
         float gearAdjustment = computeTotalGearTuning(player);
         if (!sIndividualProgression->hasPassedProgression(player, PROGRESSION_NAXX40))
         {
-            damage *= (sIndividualProgression->vanillaPowerAdjustment - gearAdjustment);
+            damage *= (sIndividualProgression->ComputeVanillaAdjustment(player, sIndividualProgression->vanillaPowerAdjustment) - gearAdjustment);
         }
         else if (!sIndividualProgression->hasPassedProgression(player, PROGRESSION_TBC_TIER_5))
         {
@@ -545,7 +551,7 @@ public:
         float gearAdjustment = computeTotalGearTuning(player);
         if (!sIndividualProgression->hasPassedProgression(player, PROGRESSION_NAXX40))
         {
-            damage *= (sIndividualProgression->vanillaPowerAdjustment - gearAdjustment);
+            damage *= (sIndividualProgression->ComputeVanillaAdjustment(player, sIndividualProgression->vanillaPowerAdjustment) - gearAdjustment);
         }
         else if (!sIndividualProgression->hasPassedProgression(player, PROGRESSION_TBC_TIER_5))
         {