Fix increased Enemy damage taken mods doubling their affect in Ailment calcs (PathOfBuildingCommunity#1819)

* Added de-duping to ailment type caculation to fix double counting in bleed and poison.

* Better fix

The mod was only there to handle elemental damage taken mods so now it is simplified
Also adds a test to make sure it works correctly

---------

Co-authored-by: Andrew Klotz <andrewsklotz@gamil.com>
Co-authored-by: LocalIdentity <localidentity2@gmail.com>

Author: 3 people

spec/System/TestAilments_spec.lua

@@ -14,4 +14,18 @@ describe("TestAilments", function()
 	--TODO: Shock not supported currently
 	--it("bleed is buffed by bleed chance", function()
 	--end)
-end)
+
+	it("does not double count chaos damage taken for chaos poison", function()
+		build.skillsTab:PasteSocketGroup("Chaos Bolt 1/0  1\nPoison I 1/0  1\n")
+		runCallback("OnFrame")
+
+		local baseEffMult = build.calcsTab.mainOutput.PoisonEffMult
+		assert.True(baseEffMult and baseEffMult > 0)
+
+		build.configTab.input.customMods = "Nearby enemies take 10% increased Chaos Damage"
+		build.configTab:BuildModList()
+		runCallback("OnFrame")
+
+		assert.are.equals(1.1, build.calcsTab.mainOutput.PoisonEffMult)
+	end)
+end)

src/Modules/CalcOffence.lua

@@ -4882,8 +4882,9 @@ function calcs.offence(env, actor, activeSkill)
 						end
 					else
 						local resist = calcResistForType(ailmentDamageType, dotCfg)
-						local takenInc = enemyDB:Sum("INC", dotCfg, "DamageTaken", "DamageTakenOverTime", ailmentDamageType .. "DamageTaken", ailmentDamageType .. "DamageTakenOverTime", ailmentTypeMod .. "DamageTaken")
-						local takenMore = enemyDB:More(dotCfg, "DamageTaken", "DamageTakenOverTime", ailmentDamageType .. "DamageTaken", ailmentDamageType .. "DamageTakenOverTime", ailmentTypeMod .. "DamageTaken")
+						local elementalDamageTaken = isElemental[ailmentDamageType] and "ElementalDamageTaken" or nil
+						local takenInc = enemyDB:Sum("INC", dotCfg, "DamageTaken", "DamageTakenOverTime", ailmentDamageType .. "DamageTaken", ailmentDamageType .. "DamageTakenOverTime", elementalDamageTaken)
+						local takenMore = enemyDB:More(dotCfg, "DamageTaken", "DamageTakenOverTime", ailmentDamageType .. "DamageTaken", ailmentDamageType .. "DamageTakenOverTime", elementalDamageTaken)
 						effMult = (1 - resist / 100) * (1 + takenInc / 100) * takenMore
 						globalOutput[ailment .. "EffMult"] = effMult
 						if breakdown and effMult ~= 1 then