[pob2-port] Fix eHP value decreasing when allocating defence nodes (#9867)

* Apply changes from PathOfBuildingCommunity/PathOfBuilding-PoE2#1929

* Fix merge

* Fix test

* Fix test

---------

Co-authored-by: unrealdreamz <unrealdreamz@users.noreply.github.com>
Co-authored-by: LocalIdentity <localidentity2@gmail.com>

Author: 3 people

spec/System/TestDefence_spec.lua

@@ -1283,4 +1283,46 @@ describe("TestDefence", function()
 		assert.are.equals(0, floor(poolsRemaining.Life))
 		assert.are.equals(0, floor(poolsRemaining.OverkillDamage))
 	end)
+
+	it("limits EHP speedup when hit damage is delayed", function()
+		local function assertClose(actual, expected)
+			assert.is_true(math.abs(actual - expected) < 0.01,
+				string.format("expected %.12f, got %.12f", expected, actual))
+		end
+
+		local function calcEHP(extraMods)
+			newBuild()
+			build.configTab.input.enemyPhysicalDamage = "500"
+			build.configTab.input.enemyFireDamage = "500"
+			build.configTab.input.enemyColdDamage = "500"
+			build.configTab.input.enemyLightningDamage = "500"
+			build.configTab.input.enemyChaosDamage = "0"
+			build.configTab.input.conditionUsingFlask = true
+			build.configTab.input.customMods = [[
+				+4000 to maximum Life
+				When Hit during effect, 75% of Life loss from Damage taken occurs over 4 seconds instead
+				+75% to all Elemental Resistances
+				+75% to Chaos Resistance
+			]] .. (extraMods or "")
+			build.configTab:BuildModList()
+			runCallback("OnFrame")
+			runCallback("OnFrame")
+			local calcsOutput = build.calcsTab.calcsOutput
+			return {
+				TotalEHP = calcsOutput.TotalEHP,
+				EffectiveBlockChance = calcsOutput.EffectiveBlockChance,
+				NumberOfMitigatedDamagingHits = calcsOutput.NumberOfMitigatedDamagingHits,
+			}
+		end
+
+		local base = calcEHP()
+		local block = calcEHP("\n+10% to Block chance\n")
+
+		newBuild()
+
+		assertClose(base.TotalEHP, 17570.183511070)
+		assertClose(block.TotalEHP, 18488.832919738)
+		assertClose(block.EffectiveBlockChance, 10)
+		assert.is_true(block.TotalEHP > base.TotalEHP)
+	end)
 end)

src/Modules/CalcDefence.lua

@@ -2681,14 +2681,17 @@ function calcs.buildDefenceEstimations(env, actor)
 			end
 			iterationMultiplier = 1
 			-- to speed it up, run recursively but accelerated
-			local speedUp = data.misc.ehpCalcSpeedUp
+			-- MoM/life-loss-prevention mechanics can collapse too many hits into one
+			-- resulting in eHP jumps so we slow the acceleration.
+			local speedUp = DamageIn["LimitEHPSpeedup"] and 4 or data.misc.ehpCalcSpeedUp
 			DamageIn["cyclesRan"] = DamageIn["cyclesRan"] or false
 			local wardAvoidBreakActive = wardAvoidBreakChance < 1 and (poolTable.WardActiveChance or 0) > 0.01
 			if not DamageIn["cyclesRan"] and not wardAvoidBreakActive and poolTable.Life > 0 and DamageIn["iterations"] < maxIterations then
 				Damage = { }
 				for _, damageType in ipairs(dmgTypeList) do
 					Damage[damageType] = DamageIn[damageType] * speedUp
 				end
+				Damage["LimitEHPSpeedup"] = DamageIn["LimitEHPSpeedup"]
 				if DamageIn.GainWhenHit then
 					Damage.GainWhenHit = true
 					Damage.LifeWhenHit = DamageIn.LifeWhenHit
@@ -2740,6 +2743,7 @@ function calcs.buildDefenceEstimations(env, actor)
 			for _, damageType in ipairs(dmgTypeList) do
 				DamageIn[damageType] = output[damageType.."TakenHit"]
 			end
+			DamageIn["LimitEHPSpeedup"] = output["preventedLifeLossTotal"] > 0
 			output["NumberOfDamagingHits"] = numberOfHitsToDie(DamageIn)
 		end
 
@@ -2834,6 +2838,7 @@ function calcs.buildDefenceEstimations(env, actor)
 				output["LifeLossLostOverTime"] = 0
 				output["LifeBelowHalfLossLostOverTime"] = 0
 			end
+			DamageIn["LimitEHPSpeedup"] = DamageIn["TrackRecoupable"] or DamageIn["TrackLifeLossOverTime"] or DamageIn.GainWhenHit
 			averageAvoidChance = averageAvoidChance / 5
 			output["ConfiguredDamageChance"] = 100 * (blockEffect * suppressionEffect * (1 - averageAvoidChance / 100))
 			output["NumberOfMitigatedDamagingHits"] = (output["ConfiguredDamageChance"] ~= 100 or DamageIn["TrackRecoupable"] or DamageIn["TrackLifeLossOverTime"] or DamageIn.GainWhenHit) and numberOfHitsToDie(DamageIn) or output["NumberOfDamagingHits"]