From 9e3285a791a7e63b5f4e9b72a02ba5e25e5cea5d Mon Sep 17 00:00:00 2001
From: Griatch <griatch@gmail.com>
Date: Sun, 8 Sep 2019 20:17:04 +0200
Subject: [PATCH] Handle drop with drop:holds() lock. Default to pass for
 backwards-compatibilty while on Evennia 0.9. See #1868

---
 CHANGELOG.md               |  3 +++
 evennia/objects/objects.py | 18 +++++++++++++-----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1305c857c8..2a9bc3ed65 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## Evennia 1.0 (2019-) (WIP)
 
+- new `drop:holds()` lock default to limit dropping nonsensical things. Access check
+  defaults to True for backwards-compatibility in 0.9, will be False in 1.0
+
 ### Already in master
 
 - `py` command now reroutes stdout to output results in-game client. `py`
diff --git a/evennia/objects/objects.py b/evennia/objects/objects.py
index 9fe152513e..bb6f6b5c64 100644
--- a/evennia/objects/objects.py
+++ b/evennia/objects/objects.py
@@ -194,7 +194,8 @@ class DefaultObject(with_metaclass(TypeclassBase, ObjectDB)):
     """
     # lockstring of newly created objects, for easy overloading.
     # Will be formatted with the appropriate attributes.
-    lockstring = "control:id({account_id}) or perm(Admin);delete:id({account_id}) or perm(Admin)"
+    lockstring = ("control:id({account_id}) or perm(Admin);"
+                  "delete:id({account_id}) or perm(Admin)")
 
     objects = ObjectManager()
 
@@ -1132,13 +1133,14 @@ class DefaultObject(with_metaclass(TypeclassBase, ObjectDB)):
 
         self.locks.add(";".join([
             "control:perm(Developer)",  # edit locks/permissions, delete
-            "examine:perm(Builder)",   # examine properties
+            "examine:perm(Builder)",    # examine properties
             "view:all()",               # look at object (visibility)
-            "edit:perm(Admin)",       # edit properties/attributes
-            "delete:perm(Admin)",     # delete object
+            "edit:perm(Admin)",         # edit properties/attributes
+            "delete:perm(Admin)",       # delete object
             "get:all()",                # pick up object
+            "drop:holds()"              # drop only that which you hold
             "call:true()",              # allow to call commands on this object
-            "tell:perm(Admin)",        # allow emits to this object
+            "tell:perm(Admin)",         # allow emits to this object
             "puppet:pperm(Developer)"]))  # lock down puppeting only to staff by default
 
     def basetype_posthook_setup(self):
@@ -1752,6 +1754,12 @@ class DefaultObject(with_metaclass(TypeclassBase, ObjectDB)):
             before it is even started.
 
         """
+        if not self.locks.get("drop"):
+            # TODO: This if-statment will be removed in Evennia 1.0
+            return True
+        if not self.access(dropper, 'drop', default=False):
+            dropper.msg(f"You cannot drop {self.get_display_name(dropper)}")
+            return False
         return True
 
     def at_drop(self, dropper, **kwargs):