Corpses with clients in them can no longer perform mech actions (#88959)

## About The Pull Request

Turns out most mech actions only cared about the person attempting to
use them being inside the mech, without checking for things such as the
mob being alive. This fixes that, but required a slight refactoring to
the `ui_status` proc of mechs to account for the three fundamentally
different types of mobs that can pilot a mech.

## Why It's Good For The Game

Fixes #88933

## Changelog

🆑
fix: Corpses at the pilot seat of mechs can no longer toggle the lights,
safeties, cabin sealing, strafing, overclocking, or durand shields, nor
can they rename the mech or configure its equipment.
/🆑

code/modules/tgui/status_composers.dm

@@ -50,7 +50,9 @@
 
 /// Returns a UI status such that those without blocked hands will be able to interact,
 /// but everyone else can only watch.
-/proc/ui_status_user_has_free_hands(mob/user, atom/source)
+/proc/ui_status_user_has_free_hands(mob/user, atom/source, allowed_source)
+	if(allowed_source)
+		return HAS_TRAIT_NOT_FROM(user, TRAIT_HANDS_BLOCKED, allowed_source) ? UI_UPDATE : UI_INTERACTIVE
 	return HAS_TRAIT(user, TRAIT_HANDS_BLOCKED) ? UI_UPDATE : UI_INTERACTIVE
 
 /// Returns a UI status such that advanced tool users will be able to interact,
@@ -110,3 +112,11 @@
 		return UI_CLOSE
 
 	return UI_INTERACTIVE
+
+/// Return UI_INTERACTIVE if the user is inside the target atom, whether they can see it or not.
+/// Return UI_CLOSE otherwise.
+/proc/ui_status_user_inside(mob/user, atom/target)
+	if(target.contains(user))
+		return UI_INTERACTIVE
+
+	return UI_CLOSE

code/modules/vehicles/mecha/combat/durand.dm

@@ -143,7 +143,9 @@ Expects a turf. Returns true if the attack should be blocked, false if not.*/
 	button_icon_state = "mech_defense_mode_off"
 
 /datum/action/vehicle/sealed/mecha/mech_defense_mode/Trigger(trigger_flags, forced_state = FALSE)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 	SEND_SIGNAL(chassis, COMSIG_MECHA_ACTION_TRIGGER, owner, args) //Signal sent to the mech, to be handed to the shield. See durand.dm for more details
 

code/modules/vehicles/mecha/combat/marauder.dm

@@ -59,7 +59,9 @@
 	button_icon_state = "mech_smoke"
 
 /datum/action/vehicle/sealed/mecha/mech_smoke/Trigger(trigger_flags)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 	if(TIMER_COOLDOWN_FINISHED(src, COOLDOWN_MECHA_SMOKE) && chassis.smoke_charges>0)
 		chassis.smoke_system.start()
@@ -71,7 +73,9 @@
 	button_icon_state = "mech_zoom_off"
 
 /datum/action/vehicle/sealed/mecha/mech_zoom/Trigger(trigger_flags)
-	if(!owner?.client || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!owner.client || !chassis || !(owner in chassis.occupants))
 		return
 	chassis.zoom_mode = !chassis.zoom_mode
 	button_icon_state = "mech_zoom_[chassis.zoom_mode ? "on" : "off"]"

code/modules/vehicles/mecha/combat/phazon.dm

@@ -42,7 +42,9 @@
 	button_icon_state = "mech_damtype_brute"
 
 /datum/action/vehicle/sealed/mecha/mech_switch_damtype/Trigger(trigger_flags)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 	var/new_damtype
 	switch(chassis.damtype)
@@ -65,7 +67,9 @@
 	button_icon_state = "mech_phasing_off"
 
 /datum/action/vehicle/sealed/mecha/mech_toggle_phasing/Trigger(trigger_flags)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 	chassis.phasing = chassis.phasing ? "" : "phasing"
 	button_icon_state = "mech_phasing_[chassis.phasing ? "on" : "off"]"

code/modules/vehicles/mecha/combat/savannah_ivanov.dm

@@ -81,6 +81,8 @@
 	var/skyfall_charge_level = 0
 
 /datum/action/vehicle/sealed/mecha/skyfall/Trigger(trigger_flags)
+	if(!..())
+		return
 	if(!owner || !chassis || !(owner in chassis.occupants))
 		return
 	if(chassis.phasing)
@@ -251,7 +253,9 @@
 	return ..()
 
 /datum/action/vehicle/sealed/mecha/ivanov_strike/Trigger(trigger_flags)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 	if(TIMER_COOLDOWN_RUNNING(chassis, COOLDOWN_MECHA_MISSILE_STRIKE))
 		var/timeleft = S_TIMER_COOLDOWN_TIMELEFT(chassis, COOLDOWN_MECHA_MISSILE_STRIKE)

code/modules/vehicles/mecha/mecha_actions.dm

@@ -24,7 +24,7 @@
 	button_icon_state = "mech_eject"
 
 /datum/action/vehicle/sealed/mecha/mech_eject/Trigger(trigger_flags)
-	if(!owner)
+	if(!..())
 		return
 	if(!chassis || !(owner in chassis.occupants))
 		return
@@ -36,7 +36,9 @@
 	desc = "Airtight cabin preserves internal air and can be pressurized with a mounted air tank."
 
 /datum/action/vehicle/sealed/mecha/mech_toggle_cabin_seal/Trigger(trigger_flags)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 	chassis.set_cabin_seal(owner, !chassis.cabin_sealed)
 
@@ -45,7 +47,9 @@
 	button_icon_state = "mech_lights_off"
 
 /datum/action/vehicle/sealed/mecha/mech_toggle_lights/Trigger(trigger_flags)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 	chassis.toggle_lights(user = owner)
 
@@ -54,7 +58,9 @@
 	button_icon_state = "mech_view_stats"
 
 /datum/action/vehicle/sealed/mecha/mech_view_stats/Trigger(trigger_flags)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 
 	chassis.ui_interact(owner)
@@ -68,7 +74,9 @@
 	RegisterSignal(chassis, COMSIG_MECH_SAFETIES_TOGGLE, PROC_REF(update_action_icon))
 
 /datum/action/vehicle/sealed/mecha/mech_toggle_safeties/Trigger(trigger_flags)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 
 	chassis.set_safety(owner)
@@ -86,7 +94,9 @@
 	button_icon_state = "strafe"
 
 /datum/action/vehicle/sealed/mecha/strafe/Trigger(trigger_flags)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 
 	chassis.toggle_strafe()
@@ -114,7 +124,9 @@
 	button_icon_state = "mech_seat_swap"
 
 /datum/action/vehicle/sealed/mecha/swap_seat/Trigger(trigger_flags)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 
 	if(chassis.occupants.len == chassis.max_occupants)
@@ -143,7 +155,9 @@
 	button_icon_state = "mech_overload_off"
 
 /datum/action/vehicle/sealed/mecha/mech_overclock/Trigger(trigger_flags, forced_state = null)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 	chassis.toggle_overclock(forced_state)
 	button_icon_state = "mech_overload_[chassis.overclock_mode ? "on" : "off"]"

code/modules/vehicles/mecha/mecha_ui.dm

@@ -10,18 +10,22 @@
 		ui_view.display_to(user)
 
 /obj/vehicle/sealed/mecha/ui_status(mob/user, datum/ui_state/state)
-	if(contains(user))
-		return UI_INTERACTIVE
-	return min(
+	var/common_status = min(
 		ui_status_user_is_abled(user, src),
-		ui_status_user_has_free_hands(user, src),
-		ui_status_user_is_advanced_tool_user(user),
 		ui_status_only_living(user),
-		max(
-			ui_status_user_is_adjacent(user, src),
-			ui_status_silicon_has_access(user, src),
-		)
 	)
+	var/mob_specific_status = UI_INTERACTIVE
+	if(ishuman(user))
+		mob_specific_status = min(
+			ui_status_user_inside(user, src),
+			ui_status_user_has_free_hands(user, src, allowed_source = VEHICLE_TRAIT),
+			ui_status_user_is_advanced_tool_user(user),
+		)
+	if(isAI(user))
+		mob_specific_status = ui_status_silicon_has_access(user, src)
+	if(isbrain(user))
+		mob_specific_status = ui_status_user_inside(user, src)
+	return min(common_status, mob_specific_status)
 
 /obj/vehicle/sealed/mecha/ui_assets(mob/user)
 	return list(

code/modules/vehicles/mecha/working/clarke.dm

@@ -121,6 +121,8 @@
 	button_icon_state = "mecha_sleeper_miner"
 
 /datum/action/vehicle/sealed/mecha/clarke_scoop_body/Trigger(trigger_flags)
+	if(!..())
+		return
 	var/obj/item/mecha_parts/mecha_equipment/sleeper/clarke/sleeper = locate() in chassis
 	var/mob/living/carbon/human/human_target
 	for(var/mob/living/carbon/human/body in range(1, chassis))
@@ -138,7 +140,9 @@
 	COOLDOWN_DECLARE(search_cooldown)
 
 /datum/action/vehicle/sealed/mecha/mech_search_ruins/Trigger(trigger_flags)
-	if(!owner || !chassis || !(owner in chassis.occupants))
+	if(!..())
+		return
+	if(!chassis || !(owner in chassis.occupants))
 		return
 	if(!COOLDOWN_FINISHED(src, search_cooldown))
 		chassis.balloon_alert(owner, "on cooldown!")

code/modules/vehicles/mecha/working/ripley.dm

@@ -181,6 +181,8 @@
 	button_icon_state = "mech_siren_[secmech?.siren ? "on" : "off"]"
 
 /datum/action/vehicle/sealed/mecha/siren/Trigger(trigger_flags, forced_state = FALSE)
+	if(!..())
+		return
 	var/obj/vehicle/sealed/mecha/ripley/paddy/secmech = chassis
 	secmech.togglesiren()
 

code/modules/vehicles/sealed.dm

@@ -1,5 +1,6 @@
 /obj/vehicle/sealed
 	flags_1 = PREVENT_CONTENTS_EXPLOSION_1
+	interaction_flags_atom = parent_type::interaction_flags_atom | INTERACT_ATOM_IGNORE_MOBILITY
 	interaction_flags_mouse_drop = NEED_HANDS
 
 	var/enter_delay = 2 SECONDS