[MIRROR] Prevents changelings from spawning bloody spiders inside of …

…vents (Skyrat-SS13#29640)

Prevents changelings from spawning bloody spiders inside of vents (#86448)

## About The Pull Request

Closes #86192 by making the ability require the owner to be on an open
turf when casting

## Why It's Good For The Game

We probably don't want people to spawn infinite antags inside of vents
which prevents anyone from being able to see or do anything about them
without tearing every single pipe on the station

## Changelog
:cl:
fix: Changelings can no longer spawn undetectable spider eggs inside of
vents
/:cl:

Co-authored-by: SmArtKar <44720187+SmArtKar@users.noreply.github.com>
Co-authored-by: Ghom <42542238+Ghommie@users.noreply.github.com>

code/modules/antagonists/changeling/powers/spiders.dm

@@ -9,6 +9,14 @@
 	dna_cost = 1
 	req_absorbs = 3
 
+// Ensures that you cannot horrifically cheese the game by spawning spiders while in the vents
+/datum/action/changeling/spiders/can_be_used_by(mob/living/user)
+	if (!isopenturf(user.loc))
+		var/turf/user_turf = get_turf(user)
+		user_turf.balloon_alert(user, "not enough space!")
+		return FALSE
+	return ..()
+
 //Makes a spider egg cluster. Allows you enable further general havok by introducing spiders to the station.
 /datum/action/changeling/spiders/sting_action(mob/user)
 	..()