Fixes handle_fire for mobs. Especially xenos (#15134)

Co-authored-by: joep van der velden <15887760+farie82@users.noreply.github.com>

code/modules/mob/living/carbon/alien/life.dm

@@ -37,6 +37,6 @@
 
 /mob/living/carbon/alien/handle_fire()//Aliens on fire code
 	. = ..()
-	if(.) //if the mob isn't on fire anymore
+	if(!.) //if the mob isn't on fire anymore
 		return
 	adjust_bodytemperature(BODYTEMP_HEATING_MAX) //If you're on fire, you heat up!

code/modules/mob/living/carbon/human/life.dm

@@ -407,19 +407,19 @@
 
 ///FIRE CODE
 /mob/living/carbon/human/handle_fire()
-	if(..())
+	. = ..()
+	if(!.)
 		return
 	if(HEATRES in mutations)
 		return
-	if(on_fire)
-		var/thermal_protection = get_thermal_protection()
+	var/thermal_protection = get_thermal_protection()
 
-		if(thermal_protection >= FIRE_IMMUNITY_MAX_TEMP_PROTECT)
-			return
-		if(thermal_protection >= FIRE_SUIT_MAX_TEMP_PROTECT)
-			bodytemperature += 11
-		else
-			bodytemperature += (BODYTEMP_HEATING_MAX + (fire_stacks * 12))
+	if(thermal_protection >= FIRE_IMMUNITY_MAX_TEMP_PROTECT)
+		return
+	if(thermal_protection >= FIRE_SUIT_MAX_TEMP_PROTECT)
+		bodytemperature += 11
+	else
+		bodytemperature += (BODYTEMP_HEATING_MAX + (fire_stacks * 12))
 
 /mob/living/carbon/human/proc/get_thermal_protection()
 	var/thermal_protection = 0 //Simple check to estimate how protected we are against multiple temperatures

code/modules/mob/living/living_defense.dm

@@ -179,6 +179,9 @@
 	if(on_fire && fire_stacks <= 0)
 		ExtinguishMob()
 
+/**
+ * Burns a mob and slowly puts the fires out. Returns TRUE if the mob is on fire
+ */
 /mob/living/proc/handle_fire()
 	if(fire_stacks < 0) //If we've doused ourselves in water to avoid fire, dry off slowly
 		fire_stacks = min(0, fire_stacks + 1)//So we dry ourselves back to default, nonflammable.

code/modules/mob/living/silicon/robot/life.dm

@@ -144,7 +144,8 @@
 
 //Robots on fire
 /mob/living/silicon/robot/handle_fire()
-	if(..())
+	. = ..()
+	if(!.)
 		return
 	if(fire_stacks > 0)
 		fire_stacks--
@@ -152,8 +153,6 @@
 	else
 		ExtinguishMob()
 
-	//adjustFireLoss(3)
-	return
 
 /mob/living/silicon/robot/update_fire()
 	overlays -= image("icon"='icons/mob/OnFire.dmi', "icon_state"="Generic_mob_burning")

code/modules/mob/living/simple_animal/simple_animal.dm

@@ -401,7 +401,7 @@
 
 /mob/living/simple_animal/handle_fire()
 	if(!can_be_on_fire)
-		return TRUE
+		return FALSE
 	. = ..()
 	if(!.)
 		return