[MIRROR] Material container drops sheets only on object deconstruct &…

… not destroy. (#793)

* Material container drops sheets only on object deconstruct & not destroy. (#81290)

## About The Pull Request
- Fixes #81289

It has nothing to do with `dump_contents()` but with the material
container that drops its materials on `Destroy()` causing side effects.
Now it only drops sheets when an object is deconstructed but not
destroyed.

For this to work properly on all instances we have to ensure
`deconstruct()` is not overridden at least on machines for now, so they
can send `COMSIG_OBJ_DECONSTRUCT` signal. That comes in the next PR

## Changelog
:cl:
fix: deleting objects with local material storage(autolathe, drone
dispenser etc) no longer drops sheets, they only drop materials when
deconstructed
/:cl:

* Material container drops sheets only on object deconstruct & not destroy.

---------

Co-authored-by: SyncIt21 <[email protected]>

code/datums/components/material/material_container.dm

@@ -66,6 +66,9 @@
 		for(var/signal in container_signals)
 			parent.RegisterSignal(src, signal, container_signals[signal])
 
+	//drop sheets when the object is deconstructed but not deleted
+	RegisterSignal(parent, COMSIG_OBJ_DECONSTRUCT, PROC_REF(drop_sheets))
+
 	if(_mat_container_flags & MATCONTAINER_NO_INSERT)
 		return
 
@@ -75,7 +78,6 @@
 	RegisterSignal(atom_target, COMSIG_ATOM_REQUESTING_CONTEXT_FROM_ITEM, PROC_REF(on_requesting_context_from_item))
 
 /datum/component/material_container/Destroy(force)
-	retrieve_all()
 	materials = null
 	allowed_materials = null
 	return ..()
@@ -88,6 +90,11 @@
 	if(mat_container_flags & MATCONTAINER_EXAMINE)
 		RegisterSignal(parent, COMSIG_ATOM_EXAMINE, PROC_REF(on_examine))
 
+/datum/component/material_container/proc/drop_sheets()
+	SIGNAL_HANDLER
+
+	retrieve_all()
+
 /datum/component/material_container/proc/on_examine(datum/source, mob/user, list/examine_texts)
 	SIGNAL_HANDLER