From 55ab994421934849f32cd1b499e017aae297b864 Mon Sep 17 00:00:00 2001
From: Lucas Karsten <lucaskarsten@hotmail.com>
Date: Sat, 15 Aug 2026 15:00:32 -0300
Subject: [PATCH] Count exposure granted to the enemy as an exposure source

The Whispering Ice lowers the enemy's elemental resistances through an
EnemyModifier, and so does "Enemies in your Presence have Exposure".
Neither grants an ExposureChance modifier or the InflictExposure flag,
which are the only things hasExposureSource looks for, so the build ends
up in a state where the enemy has Fire Exposure while the player is said
to be unable to apply it.

Condition:CanApply<Element>Exposure gates the "Is the enemy Exposed"
config options, so with those items the options are never drawn and the
exposure cannot be inspected in the Calcs tab, even though the
resistances already reflect it.

The enemy's own exposure modifiers are now treated as a source. Exposure
still resolves to the largest single source, so enabling the config on
top of an item that already grants more does not change the result.
---
 spec/System/TestExposureSource_spec.lua | 56 +++++++++++++++++++++++++
 src/Modules/CalcPerform.lua             |  6 +++
 2 files changed, 62 insertions(+)
 create mode 100644 spec/System/TestExposureSource_spec.lua

diff --git a/spec/System/TestExposureSource_spec.lua b/spec/System/TestExposureSource_spec.lua
new file mode 100644
index 0000000000..3b5b092b6d
--- /dev/null
+++ b/spec/System/TestExposureSource_spec.lua
@@ -0,0 +1,56 @@
+describe("ExposureSource", function()
+	before_each(function()
+		newBuild()
+	end)
+
+	local function equipWhisperingIce()
+		build.itemsTab:CreateDisplayItemFromRaw([[
+			New Item
+			Permafrost Staff
+			Implicits: 0
+			Inflict Elemental Exposure on Hit, lowering Total Elemental Resistances by 60%
+		]])
+		build.itemsTab:AddDisplayItem()
+		runCallback("OnFrame")
+	end
+
+	local function canApply(element)
+		return build.calcsTab.calcsEnv.modDB:Flag(nil, "Condition:CanApply" .. element .. "Exposure") == true
+	end
+
+	local function enemyResist(element)
+		return build.calcsTab.calcsEnv.enemyDB:Sum("BASE", nil, element .. "Resist")
+	end
+
+	it("counts exposure granted directly to the enemy as a source", function()
+		equipWhisperingIce()
+
+		-- Without this the enemy is exposed while the build is told it cannot
+		-- expose, which hides the "Is the enemy Exposed" config entirely.
+		assert.is_true(build.calcsTab.calcsEnv.enemyDB:Flag(nil, "Condition:HasFireExposure") == true)
+		for _, element in ipairs({ "Fire", "Cold", "Lightning" }) do
+			assert.is_true(canApply(element))
+		end
+	end)
+
+	it("does not report a source when nothing grants exposure", function()
+		runCallback("OnFrame")
+
+		for _, element in ipairs({ "Fire", "Cold", "Lightning" }) do
+			assert.is_false(canApply(element))
+		end
+	end)
+
+	it("keeps the largest exposure when the config is also enabled", function()
+		equipWhisperingIce()
+		local itemOnly = enemyResist("Fire")
+
+		build.configTab.input.conditionEnemyFireExposure = true
+		build.configTab:BuildModList()
+		runCallback("OnFrame")
+
+		-- Exposure does not stack: the -20% from the config must not add to the
+		-- -60% from the item.
+		assert.are.equals(itemOnly, enemyResist("Fire"))
+	end)
+end)
diff --git a/src/Modules/CalcPerform.lua b/src/Modules/CalcPerform.lua
index dbc4bb9767..bd0058197a 100644
--- a/src/Modules/CalcPerform.lua
+++ b/src/Modules/CalcPerform.lua
@@ -431,6 +431,12 @@ local function doActorAttribsConditions(env, actor)
 			if modDB:Sum("BASE", nil, modName) > 0 or modDB:HasMod("FLAG", nil, "InflictExposure") then
 				return true
 			end
+			-- Exposure granted straight to the enemy, as The Whispering Ice and
+			-- "Enemies in your Presence have Exposure" do, carries no chance mod
+			-- and no InflictExposure flag, so it has to be read off the enemy.
+			if env.enemy and env.enemy.modDB and env.enemy.modDB:Sum("BASE", nil, element .. "Exposure") > 0 then
+				return true
+			end
 			for _, activeSkill in ipairs(env.player.activeSkillList) do
 				if hasActiveSkillExposureSource(activeSkill, modName) then
 					return true