[MIRROR] Correct instances of destroying baseturfs in ChangeTurf & Select dimensional anomaly theme [MDB IGNORE] (#19255)

* Correct instances of destroying baseturfs in ChangeTurf & Select dimensional anomaly theme

* events

---------

Co-authored-by: Jacquerel <hnevard@gmail.com>
Co-authored-by: lessthnthree <three@lessthanthree.dk>
Co-authored-by: Gandalf <9026500+Gandalf2k15@users.noreply.github.com>

code/game/objects/effects/anomalies/anomalies_dimensional.dm

@@ -42,10 +42,12 @@
 
 /**
  * Prepare a new area for transformation into a new theme.
+ * Optionally pass in the typepath of an anomaly theme to use that one.
  */
-/obj/effect/anomaly/dimensional/proc/prepare_area()
-	var/datum/dimension_theme/themes = new()
-	theme = themes.get_random_theme()
+/obj/effect/anomaly/dimensional/proc/prepare_area(new_theme_path)
+	if (!new_theme_path)
+		new_theme_path = pick(subtypesof(/datum/dimension_theme))
+	theme = new new_theme_path()
 	apply_theme_icon()
 
 	target_turfs = new()

code/game/objects/effects/anomalies/anomalies_dimensional_themes.dm

@@ -32,13 +32,6 @@
 		var/datum/material/using_mat = GET_MATERIAL_REF(material)
 		window_colour = using_mat.greyscale_colors
 
-/**
- * Returns a subtype of dimensional theme.
- */
-/datum/dimension_theme/proc/get_random_theme()
-	var/subtype = pick(subtypesof(/datum/dimension_theme))
-	return new subtype()
-
 /**
  * Applies themed transformation to the provided turf.
  *
@@ -105,7 +98,7 @@
 /datum/dimension_theme/proc/transform_floor(turf/open/floor/affected_floor)
 	if (replace_floors.len == 0)
 		return FALSE
-	affected_floor.ChangeTurf(pick_weight(replace_floors), flags = CHANGETURF_INHERIT_AIR)
+	affected_floor.replace_floor(pick_weight(replace_floors), flags = CHANGETURF_INHERIT_AIR)
 	return TRUE
 
 /**
@@ -191,6 +184,7 @@
 		if (!permit_replace_material(thing))
 			continue
 		thing.set_custom_materials(custom_materials)
+		thing.update_appearance(updates = UPDATE_ICON)
 
 #undef PERMITTED_MATERIAL_REPLACE_TYPES