Simple build permissions feature. NOTE: EXPERIMENTAL, DISABLED BY DEFAULT. Turns out that this can't be expressed by cascading Permission modules, so I did it as per this patch.

OpenSim/Framework/ILandObject.cs

@@ -63,6 +63,7 @@ namespace OpenSim.Framework
         bool ContainsPoint(int x, int y);
         
         ILandObject Copy();
+        ILandObject MemberwiseCopy();
 
         void SendLandUpdateToAvatarsOverMe();
 
@@ -70,6 +71,7 @@ namespace OpenSim.Framework
         void UpdateLandProperties(LandUpdateArgs args, IClientAPI remote_client);
         bool IsEitherBannedOrRestricted(UUID avatar);
         bool IsBannedFromLand(UUID avatar);
+        bool IsAllowedInLand(UUID avatar);
         bool IsRestrictedFromLand(UUID avatar);
         void SendLandUpdateToClient(IClientAPI remote_client);
         void SendLandUpdateToClient(bool snap_selection, IClientAPI remote_client);

OpenSim/Region/CoreModules/World/Land/LandObject.cs

@@ -169,6 +169,11 @@ namespace OpenSim.Region.CoreModules.World.Land
             return newLand;
         }
 
+        public ILandObject MemberwiseCopy()
+        {
+            return (ILandObject)this.MemberwiseClone();
+        }
+
         static overrideParcelMaxPrimCountDelegate overrideParcelMaxPrimCount;
         static overrideSimulatorMaxPrimCountDelegate overrideSimulatorMaxPrimCount;
 
@@ -242,8 +247,10 @@ namespace OpenSim.Region.CoreModules.World.Land
                 m_lastSeqId = seq_id;
             }
 
+            ILandObject landToSend = this;
+            m_scene.Permissions.LandObjectForClient(remote_client.AgentId, (ILandObject)this, out landToSend);
             remote_client.SendLandProperties(seq_id,
-                    snap_selection, request_result, this,
+                        snap_selection, request_result, landToSend,
                         (float)m_scene.RegionInfo.RegionSettings.ObjectBonus,
                         GetParcelMaxPrimCount(),
                         GetSimulatorMaxPrimCount(), regionFlags);
@@ -475,6 +482,32 @@ namespace OpenSim.Region.CoreModules.World.Land
             return false;
         }
 
+        public bool IsAllowedInLand(UUID avatar)
+        {
+            ExpireAccessList();
+
+            if (m_scene.Permissions.IsAdministrator(avatar))
+                return true;
+
+            if (m_scene.RegionInfo.EstateSettings.IsEstateManager(avatar))
+                return true;
+
+            if (avatar == LandData.OwnerID)
+                return true;
+
+            if (LandData.ParcelAccessList.FindIndex(
+                        delegate(LandAccessEntry e)
+                        {
+                            if (e.AgentID == avatar && e.Flags == AccessList.Access)
+                                return true;
+                            return false;
+                        }) != -1)
+                {
+                    return true;
+                }
+            return false;
+        }
+
         public void SendLandUpdateToClient(IClientAPI remote_client)
         {
             SendLandProperties(0, false, 0, remote_client);

OpenSim/Region/CoreModules/World/Permissions/PermissionsModule.cs

@@ -95,6 +95,8 @@ namespace OpenSim.Region.CoreModules.World.Permissions
         private bool m_RegionManagerIsGod = false;
         private bool m_ParcelOwnerIsGod = false;
 
+        private bool m_SimpleBuildPermissions = false;
+
         /// <value>
         /// The set of users that are allowed to create scripts.  This is only active if permissions are not being
         /// bypassed.  This overrides normal permissions.
@@ -140,6 +142,8 @@ namespace OpenSim.Region.CoreModules.World.Permissions
             m_RegionManagerIsGod = myConfig.GetBoolean("region_manager_is_god", false);
             m_ParcelOwnerIsGod = myConfig.GetBoolean("parcel_owner_is_god", true);
 
+            m_SimpleBuildPermissions = myConfig.GetBoolean("simple_build_permissions", false);
+
             m_allowedScriptCreators 
                 = ParseUserSetConfigSetting(myConfig, "allowed_script_creators", m_allowedScriptCreators);
             m_allowedScriptEditors
@@ -206,6 +210,9 @@ namespace OpenSim.Region.CoreModules.World.Permissions
             m_scene.Permissions.OnControlPrimMedia += CanControlPrimMedia;
             m_scene.Permissions.OnInteractWithPrimMedia += CanInteractWithPrimMedia;
 
+            if (m_SimpleBuildPermissions)
+                m_scene.Permissions.OnSendLandProperties += GenerateLandProperties;
+
             m_scene.AddCommand("Users", this, "bypass permissions",
                     "bypass permissions <true / false>",
                     "Bypass permission checks",
@@ -824,6 +831,10 @@ namespace OpenSim.Region.CoreModules.World.Permissions
                 permission = true;
             }
 
+            if (m_SimpleBuildPermissions &&
+                (parcel.LandData.Flags & (uint)ParcelFlags.UseAccessList) == 0 && parcel.IsAllowedInLand(user))
+                permission = true;
+
             return permission;
         }
     
@@ -1966,5 +1977,24 @@ namespace OpenSim.Region.CoreModules.World.Permissions
             
             return false;
         }
+
+        private void GenerateLandProperties(UUID userID, ILandObject realLand, out ILandObject landToSend)
+        {
+            landToSend = realLand;
+            if (m_bypassPermissions) return;
+
+            if (m_SimpleBuildPermissions &&
+                !m_scene.Permissions.IsAdministrator(userID) &&
+                !realLand.LandData.OwnerID.Equals(userID) &&
+                ((realLand.LandData.Flags & (uint)ParcelFlags.UseAccessList) == 0 && realLand.IsAllowedInLand(userID)))
+            {
+                ILandObject clone = realLand.MemberwiseCopy();
+                LandData ldata = realLand.LandData.Copy();
+                clone.LandData = ldata;
+                clone.LandData.Flags |= (uint)(ParcelFlags.AllowAPrimitiveEntry | ParcelFlags.AllowFly | ParcelFlags.AllowOtherScripts | ParcelFlags.CreateObjects);
+                landToSend = clone;
+            }
+        }
+
     }
 }

OpenSim/Region/Framework/Scenes/Scene.Permissions.cs

@@ -90,6 +90,7 @@ namespace OpenSim.Region.Framework.Scenes
     public delegate bool TeleportHandler(UUID userID, Scene scene);
     public delegate bool ControlPrimMediaHandler(UUID userID, UUID primID, int face);
     public delegate bool InteractWithPrimMediaHandler(UUID userID, UUID primID, int face);
+    public delegate void SendLandPropertiesHandler(UUID userID, ILandObject realLand, out ILandObject landToSend);
     #endregion
 
     public class ScenePermissions
@@ -157,6 +158,7 @@ namespace OpenSim.Region.Framework.Scenes
         public event TeleportHandler OnTeleport;
         public event ControlPrimMediaHandler OnControlPrimMedia;
         public event InteractWithPrimMediaHandler OnInteractWithPrimMedia;
+        public event SendLandPropertiesHandler OnSendLandProperties;
         #endregion
 
         #region Object Permission Checks
@@ -1098,5 +1100,20 @@ namespace OpenSim.Region.Framework.Scenes
             }
             return true;
         }
+
+        public void LandObjectForClient(UUID userID, ILandObject realLand, out ILandObject landToSend)
+        {
+            landToSend = realLand;
+            SendLandPropertiesHandler handler = OnSendLandProperties;
+            if (handler != null)
+            {
+                Delegate[] list = handler.GetInvocationList();
+                foreach (SendLandPropertiesHandler h in list)
+                {
+                    h(userID, realLand, out landToSend);
+                }
+            }
+        }
+
     }
 }

bin/OpenSim.ini.example

@@ -194,6 +194,14 @@
     ; region_manager_is_god = false
     ; parcel_owner_is_god = true
 
+    ;; More control over permissions
+    ;; This is definitely not SL!
+    ; Provides a simple control for land owners to give build rights to specific avatars
+    ; in publicly accessible parcels that disallow object creation in general. 
+    ; Owners specific avatars by adding them to the Access List of the parcel
+    ; without having to use the Groups feature
+    ; simple_build_permissions = false
+
     ;; Default script engine to use. Currently, we only have XEngine
     ; DefaultScriptEngine = "XEngine"
 

bin/OpenSimDefaults.ini

@@ -260,6 +260,13 @@
     ; Default value is all
     ; allowed_script_editors = all
 
+    ; Provides a simple control for land owners to give build rights to
+    ; publicly accessible parcels that disallow object creation in general. 
+    ; Owners specific avatars by adding them to the Access List of the parcel
+    ; without having to use the Groups feature
+    ; Disabled by default
+    ; simple_build_permissions = False
+
     ; ##
     ; ## SCRIPT ENGINE
     ; ##