Thanks, lulurun, for a patch that addresses inventory problems that occur

occasionally, but are fixed on restart (issue 1919).
This patch introduces the following changes:
1. when a user teleports out of Region A, remove that user's profile
from the Region A user profile cache
2. when a user crosses between regions out of Region A, remove that
user's profile from the Region A user profile cache
3. the user profile cache's session ID member can now be set (written),
and is updated each time a connection with a new avatar is established (ie: a
new avatar enters the region)
4. when a region server looks up a user profile and a cache miss
occurs, fetch the user profile from the user server first instead of
immediately returning null

OpenSim/Framework/Communications/Cache/CachedUserInfo.cs

@@ -86,7 +86,11 @@ namespace OpenSim.Framework.Communications.Cache
         private IDictionary<LLUUID, IList<InventoryFolderImpl>> pendingCategorizationFolders
             = new Dictionary<LLUUID, IList<InventoryFolderImpl>>();
 
-        public LLUUID SessionID { get { return m_session_id; } }
+        public LLUUID SessionID
+        {
+            get { return m_session_id; }
+            set { m_session_id = value; }
+        }
         private LLUUID m_session_id = LLUUID.Zero;        
         
         /// <summary>
@@ -100,21 +104,6 @@ namespace OpenSim.Framework.Communications.Cache
             m_userProfile = userProfile;
         }
 
-        /// <summary>
-        /// Constructor
-        /// </summary>
-        /// <param name="commsManager"></param>
-        /// <param name="userProfile"></param>
-        /// <param name="sessionId">
-        /// Session id of the user.  This is used in subsequent security checks.
-        /// </param>
-        public CachedUserInfo(CommunicationsManager commsManager, UserProfileData userProfile, LLUUID sessionId)
-        {
-            m_commsManager = commsManager;
-            m_userProfile = userProfile;
-            m_session_id = sessionId;
-        }
-
         /// <summary>
         /// This allows a request to be added to be processed once we receive a user's inventory
         /// from the inventory service.  If we already have the inventory, the request

OpenSim/Framework/Communications/Cache/UserProfileCacheService.cs

@@ -59,35 +59,6 @@ namespace OpenSim.Framework.Communications.Cache
             m_commsManager = commsManager;
         }
 
-        /// <summary>
-        /// A new user has moved into a region in this instance so retrieve their profile from the user service.
-        /// </summary>
-        /// <param name="userID"></param>
-        public void AddNewUser(IClientAPI remoteClient)
-        {
-            m_log.DebugFormat("[USER CACHE]: Adding user profile for {0} {1}", remoteClient.Name, remoteClient.AgentId);
-            
-            // Potential fix - Multithreading issue.
-            lock (m_userProfiles)
-            {
-                if (!m_userProfiles.ContainsKey(remoteClient.AgentId))
-                {
-                    UserProfileData userProfile = m_commsManager.UserService.GetUserProfile(remoteClient.AgentId);
-                    CachedUserInfo userInfo = new CachedUserInfo(m_commsManager, userProfile, remoteClient.SessionId);
-
-                    if (userInfo.UserProfile != null)
-                    {
-                        // The inventory for the user will be populated when they actually enter the scene
-                        m_userProfiles.Add(remoteClient.AgentId, userInfo);
-                    }
-                    else
-                    {
-                        m_log.ErrorFormat("[USER CACHE]: User profile for user {0} not found.", remoteClient.AgentId);
-                    }
-                }
-            }
-        }
-
         /// <summary>
         /// A new user has moved into a region in this instance so retrieve their profile from the user service.
         /// </summary>
@@ -95,26 +66,7 @@ namespace OpenSim.Framework.Communications.Cache
         public void AddNewUser(LLUUID userID)
         {
             m_log.DebugFormat("[USER CACHE]: Adding user profile for {0}", userID);
-            
+            GetUserDetails(userID);
-            // Potential fix - Multithreading issue.
-            lock (m_userProfiles)
-            {
-                if (!m_userProfiles.ContainsKey(userID))
-                {
-                    UserProfileData userProfile = m_commsManager.UserService.GetUserProfile(userID);
-                    CachedUserInfo userInfo = new CachedUserInfo(m_commsManager, userProfile);
-
-                    if (userInfo.UserProfile != null)
-                    {
-                        // The inventory for the user will be populated when they actually enter the scene
-                        m_userProfiles.Add(userID, userInfo);
-                    }
-                    else
-                    {
-                        m_log.ErrorFormat("[USER CACHE]: User profile for user {0} not found.", userID);
-                    }
-                }
-            }
         }
 
         /// <summary>
@@ -175,12 +127,30 @@ namespace OpenSim.Framework.Communications.Cache
         /// <param name="userID"></param>
         /// <returns>null if no user details are found</returns>
         public CachedUserInfo GetUserDetails(LLUUID userID)
+        {
+            lock (m_userProfiles)
             {
                 if (m_userProfiles.ContainsKey(userID))
+                {
                     return m_userProfiles[userID];
+                }
                 else
+                {
+                    UserProfileData userprofile = m_commsManager.UserService.GetUserProfile(userID);
+                    if (userprofile != null)
+                    {
+                        CachedUserInfo userinfo = new CachedUserInfo(m_commsManager, userprofile);
+                        m_userProfiles.Add(userID, userinfo);
+                        return userinfo;
+                    }
+                    else
+                    {
+                        m_log.ErrorFormat("[USER CACHE]: User profile for user {0} not found.", userID);
                         return null;
                     }
+                }
+            }
+        }
 
         /// <summary>
         /// Handle an inventory folder creation request from the client.

OpenSim/Region/Environment/Scenes/Scene.cs

@@ -2015,7 +2015,7 @@ namespace OpenSim.Region.Environment.Scenes
                     "[SCENE]: Adding new {0} agent {1} {2} in {3}", 
                     (child ? "child" : "root"), client.Name, client.AgentId, RegionInfo.RegionName);
 
-                CommsManager.UserProfileCacheService.AddNewUser(client);
+                CommsManager.UserProfileCacheService.AddNewUser(client.AgentId);
 
                 CreateAndAddScenePresence(client, child);
             }
@@ -2455,6 +2455,9 @@ namespace OpenSim.Region.Environment.Scenes
                     agent.circuitcode, agent.AgentID, RegionInfo.RegionName);
 
                 m_authenticateHandler.AddNewCircuit(agent.circuitcode, agent);
+                // rewrite session_id
+                CachedUserInfo userinfo = CommsManager.UserProfileCacheService.GetUserDetails(agent.AgentID);
+                userinfo.SessionID = agent.SessionID;
             }
             else
             {

OpenSim/Region/Environment/Scenes/SceneCommunicationService.cs

@@ -627,6 +627,11 @@ namespace OpenSim.Region.Environment.Scenes
                         {
                             SendCloseChildAgentConnections(avatar.UUID,avatar.GetKnownRegionList());
                         }
+                        // if (teleport success) // seems to be always success here
+                        // the user may change thier profile information in other region,
+                        // so the userinfo in UserProfileCache is not reliable any more, delete it
+                        m_commsProvider.UserProfileCacheService.RemoveUser(avatar.UUID);
+                        m_log.InfoFormat("User {0} is going to another region, profile cache removed", avatar.UUID);
                     }
                     else
                     {

OpenSim/Region/Environment/Scenes/ScenePresence.cs

@@ -1989,6 +1989,10 @@ namespace OpenSim.Region.Environment.Scenes
                         
                     m_scene.SendKillObject(m_localId);
                     m_scene.NotifyMyCoarseLocationChange();
+                    // the user may change thier profile information in other region,
+                    // so the userinfo in UserProfileCache is not reliable any more, delete it
+                    m_scene.CommsManager.UserProfileCacheService.RemoveUser(UUID);
+                    m_log.InfoFormat("User {0} is going to another region, profile cache removed", UUID);
                 }
                 else
                 {