From d5601f9acee370f5d3399edf5b9eef5c2bf2f095 Mon Sep 17 00:00:00 2001
From: SkyratBot <59378654+SkyratBot@users.noreply.github.com>
Date: Sat, 7 Jan 2023 03:53:23 +0100
Subject: [PATCH] [MIRROR] Ensures area contents respects world.maxx/y
 expanding [MDB IGNORE] (#18554)

---
 code/game/world.dm             | 24 +++++++++++++++++++++++-
 code/modules/mapping/reader.dm | 26 +++++++++++++++++++++-----
 2 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/code/game/world.dm b/code/game/world.dm
index 2f0bd5e5080..5d3b959e989 100644
--- a/code/game/world.dm
+++ b/code/game/world.dm
@@ -370,12 +370,34 @@ GLOBAL_VAR(restart_counter)
 	else
 		hub_password = "SORRYNOPASSWORD"
 
+// If this is called as a part of maploading you cannot call it on the newly loaded map zs, because those get handled later on in the pipeline
+/world/proc/increaseMaxX(new_maxx, max_zs_to_load = maxz)
+	if(new_maxx <= maxx)
+		return
+	var/old_max = world.maxx
+	maxx = new_maxx
+	if(!max_zs_to_load)
+		return
+	var/area/global_area = GLOB.areas_by_type[world.area] // We're guaranteed to be touching the global area, so we'll just do this
+	var/list/to_add = block(locate(old_max + 1, 1, 1), locate(maxx, maxy, max_zs_to_load))
+	global_area.contained_turfs += to_add
+
+/world/proc/increaseMaxY(new_maxy, max_zs_to_load = maxz)
+	if(new_maxy <= maxy)
+		return
+	var/old_maxy = maxy
+	maxy = new_maxy
+	if(!max_zs_to_load)
+		return
+	var/area/global_area = GLOB.areas_by_type[world.area] // We're guarenteed to be touching the global area, so we'll just do this
+	var/list/to_add = block(locate(1, old_maxy + 1, 1), locate(maxx, maxy, max_zs_to_load))
+	global_area.contained_turfs += to_add
+
 /world/proc/incrementMaxZ()
 	maxz++
 	SSmobs.MaxZChanged()
 	SSidlenpcpool.MaxZChanged()
 
-
 /world/proc/change_fps(new_value = 20)
 	if(new_value <= 0)
 		CRASH("change_fps() called with [new_value] new_value.")
diff --git a/code/modules/mapping/reader.dm b/code/modules/mapping/reader.dm
index 9e5ab17593c..77250dcf826 100644
--- a/code/modules/mapping/reader.dm
+++ b/code/modules/mapping/reader.dm
@@ -319,8 +319,12 @@
 	var/relative_y = first_column.ycrd
 	var/highest_y = relative_y + y_relative_to_absolute
 
-	if(!cropMap && highest_y > world.maxy)
-		world.maxy = highest_y // Expand Y here. X is expanded later on
+	if(!cropMap && highest_y > world.maxx)
+		if(new_z)
+			// Need to avoid improperly loaded area/turf_contents
+			world.increaseMaxY(highest_y, max_zs_to_load = z_offset - 1)
+		else
+			world.increaseMaxY(highest_y)
 		expanded_y = TRUE
 
 	// Skip Y coords that are above the smallest of the three params
@@ -353,7 +357,11 @@
 		var/delta = max(final_x - x_delta_with, 0)
 		final_x -= delta
 	if(final_x > world.maxx && !cropMap)
-		world.maxx = final_x
+		if(new_z)
+			// Need to avoid improperly loaded area/turf_contents
+			world.increaseMaxX(final_x, max_zs_to_load = z_offset - 1)
+		else
+			world.increaseMaxX(final_x)
 		expanded_x = TRUE
 
 	var/lowest_x = max(x_lower, 1 - x_relative_to_absolute)
@@ -443,7 +451,11 @@
 		var/ycrd = relative_y + y_relative_to_absolute
 		var/zcrd = gset.zcrd + z_offset - 1
 		if(!cropMap && ycrd > world.maxy)
-			world.maxy = ycrd // Expand Y here.  X is expanded in the loop below
+			if(new_z)
+				// Need to avoid improperly loaded area/turf_contents
+				world.increaseMaxY(ycrd, max_zs_to_load = z_offset - 1)
+			else
+				world.increaseMaxY(ycrd)
 			expanded_y = TRUE
 		var/zexpansion = zcrd > world.maxz
 		var/no_afterchange = no_changeturf
@@ -495,7 +507,11 @@
 			final_x -= delta
 			x_target = x_step_count * key_len
 		if(final_x > world.maxx && !cropMap)
-			world.maxx = final_x
+			if(new_z)
+				// Need to avoid improperly loaded area/turf_contents
+				world.increaseMaxX(final_x, max_zs_to_load = z_offset - 1)
+			else
+				world.increaseMaxX(final_x)
 			expanded_x = TRUE
 
 		// We're gonna track the first and last pairs of coords we find