fixes wall mounted objects

code/__DEFINES/misc.dm

@@ -340,6 +340,12 @@ var/list/bloody_footprints_cache = list()
 /////////////////////////////////////
 // atom.appearence_flags shortcuts //
 /////////////////////////////////////
+//this was added midway thru 510, so it might not exist in some versions, but we can't check by minor verison
+#ifndef TILE_BOUND
+#warn this version of 510 is too old, You should use byond 510.1332 or later when using 510.
+#define TILE_BOUND 256
+#endif
+
 // Disabling certain features
 #define APPEARANCE_IGNORE_TRANSFORM			RESET_TRANSFORM
 #define APPEARANCE_IGNORE_COLOUR			RESET_COLOR

code/__HELPERS/510.dm

@@ -255,4 +255,4 @@
 	#undef CannotBeFlat
 	#undef CannotBeAssoc
 	#undef BadList
-#endif
+#endif

code/game/atoms_movable.dm

@@ -14,6 +14,7 @@
 	var/inertia_dir = 0
 	var/pass_flags = 0
 	glide_size = 8
+	appearance_flags = TILE_BOUND
 
 
 /atom/movable/Move(atom/newloc, direct = 0)

code/modules/atmospherics/gasmixtures/gas_types.dm

@@ -72,7 +72,7 @@ var/list/hardcoded_gases = list("o2","n2","co2","plasma") //the main four gases,
 	icon = 'icons/effects/tile_effects.dmi'
 	mouse_opacity = 0
 	layer = 5
-	appearance_flags = RESET_COLOR
+	appearance_flags = RESET_COLOR|TILE_BOUND
 
 /obj/effect/overlay/gas/New(state)
 	. = ..()