Equipping a belt of undeath or similar immediately stops suffocation

game/modules/tome/class/Actor.lua

@@ -7301,8 +7301,8 @@ end
 
 --- Suffocate a bit, lose air
 function _M:suffocate(value, src, death_message)
-	if self:attr("no_breath") then return false, false end
-	if self:attr("invulnerable") then return false, false end
+	if self:attr("no_breath") then self:removeEffect(self.EFF_SUFFOCATING) return false, false end
+	if self:attr("invulnerable") then self:removeEffect(self.EFF_SUFFOCATING) return false, false end
 	self.air = self.air - value
 	local ae = game.level.map(self.x, self.y, Map.ACTOR)
 	self.force_suffocate = true

game/modules/tome/data/timed_effects/other.lua

@@ -2672,6 +2672,15 @@ newEffect{
 			self:removeEffect(self.EFF_SUFFOCATING, false, true)
 			return
 		end
+		-- We can breathe now! What a relief!
+		local air_level, air_condition = game.level.map:checkEntity(self.x, self.y, Map.TERRAIN, "air_level"), game.level.map:checkEntity(self.x, self.y, Map.TERRAIN, "air_condition")
+		if air_level then
+			if not (not air_condition or not self.can_breath[air_condition] or self.can_breath[air_condition] <= 0) or self:attr("no_breath") or self:attr("invulnerable") then
+				self.is_suffocating = nil
+				self:removeEffect(self.EFF_SUFFOCATING, false, true)
+				return
+			end
+		end
 
 		-- Bypass all shields & such
 		local old = self.onTakeHit