* On client login, send only one terrain patch at a time (with pauses) instead of 4 at a time

* Certain terrains which are fine went patches are sent singly cause a libsecondlife failure when patches are sent in batches
* See http://opensimulator.org/mantis/view.php?id=1662 for more details

OpenSim/Region/ClientStack/LindenUDP/LLClientView.cs

@@ -1101,27 +1101,44 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             //}
         }
 
+        /// <summary>
+        /// Send terrain layer information to the client.
+        /// </summary>
+        /// <param name="o"></param>
         private void DoSendLayerData(object o)
         {
             float[] map = (float[])o;
+            
             try
             {
                 for (int y = 0; y < 16; y++)
                 {
-                    for (int x = 0; x < 16; x += 4)
+                    // For some terrains, sending more than one terrain patch at once results in a libsecondlife exception
+                    // see http://opensimulator.org/mantis/view.php?id=1662                     
+                    //for (int x = 0; x < 16; x += 4)
+                    //{
+                    //    SendLayerPacket(map, y, x);
+                    //    Thread.Sleep(150);
+                    //}
+                    for (int x= 0; x < 16; x++)
                     {
-                        SendLayerPacket(map, y, x);
+                         SendLayerData(x, y, map);
-                        Thread.Sleep(150);
+                         Thread.Sleep(35);
                     }
                 }
             }
             catch (Exception e)
             {
-                m_log.Warn("[client]: " +
+                m_log.Warn("[CLIENT]: ClientView.API.cs: SendLayerData() - Failed with exception " + e.ToString());
-                                      "ClientView.API.cs: SendLayerData() - Failed with exception " + e.ToString());
             }
         }
 
+        /// <summary>
+        /// Sends a set of four patches (x, x+1, ..., x+3) to the client
+        /// </summary>
+        /// <param name="map">heightmap</param> 
+        /// <param name="px">X coordinate for patches 0..12</param>
+        /// <param name="py">Y coordinate for patches 0..15</param>
         private void SendLayerPacket(float[] map, int y, int x)
         {
             int[] patches = new int[4];
@@ -1137,8 +1154,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         /// <summary>
         /// Sends a specified patch to a client
         /// </summary>
-        /// <param name="px">Patch coordinate (x) 0..16</param>
+        /// <param name="px">Patch coordinate (x) 0..15</param>
-        /// <param name="py">Patch coordinate (y) 0..16</param>
+        /// <param name="py">Patch coordinate (y) 0..15</param>
         /// <param name="map">heightmap</param>
         public void SendLayerData(int px, int py, float[] map)
         {
@@ -1157,8 +1174,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             }
             catch (Exception e)
             {
-                m_log.Warn("[client]: " +
+                m_log.Warn("[client]: ClientView.API.cs: SendLayerData() - Failed with exception " + e.ToString());
-                           "ClientView.API.cs: SendLayerData() - Failed with exception " + e.ToString());
             }
         }
 

OpenSim/Region/Environment/Interfaces/ITerrainChannel.cs

@@ -32,7 +32,13 @@ namespace OpenSim.Region.Environment.Interfaces
         int Height { get; }
         double this[int x, int y] { get; set; }
         int Width { get; }
+
+        /// <summary>
+        /// Squash the entire heightmap into a single dimensioned array
+        /// </summary>
+        /// <returns></returns>
         float[] GetFloatsSerialised();
+        
         double[,] GetDoubles();
         bool Tainted(int x, int y);
         ITerrainChannel MakeCopy();

OpenSim/Region/Environment/Modules/World/Terrain/TerrainChannel.cs

@@ -45,7 +45,7 @@ namespace OpenSim.Region.Environment.Modules.World.Terrain
 
         public TerrainChannel()
         {
-            map = new double[Constants.RegionSize,Constants.RegionSize];
+            map = new double[Constants.RegionSize, Constants.RegionSize];
             taint = new bool[Constants.RegionSize / 16,Constants.RegionSize / 16];
 
             int x;

OpenSim/Region/Environment/Modules/World/Terrain/TerrainModule.cs

@@ -494,8 +494,9 @@ namespace OpenSim.Region.Environment.Modules.World.Terrain
         }
 
         /// <summary>
-        /// Checks to see if the terrain has been modified since last check
+        /// Checks to see if the terrain has been modified since last check.
-        /// if the call is asked to respect the estate settings for terrain_raise_limit and
+        /// If it has been modified, every all the terrain patches are sent to the client.
+        /// If the call is asked to respect the estate settings for terrain_raise_limit and
         /// terrain_lower_limit, it will clamp terrain updates between these values
         /// currently invoked by client_OnModifyTerrain only and not the Commander interfaces
         /// <param name="respectEstateSettings">should height map deltas be limited to the estate settings limits</param>
@@ -520,6 +521,7 @@ namespace OpenSim.Region.Environment.Modules.World.Terrain
                             // what we are going to send to the client
                             serialised = m_channel.GetFloatsSerialised();
                         }
+                        
                         SendToClients(serialised, x, y);
                         shouldTaint = true;
                     }
@@ -578,7 +580,11 @@ namespace OpenSim.Region.Environment.Modules.World.Terrain
         private void SendToClients(float[] serialised, int x, int y)
         {
             m_scene.ForEachClient(
-                delegate(IClientAPI controller) { controller.SendLayerData(x / Constants.TerrainPatchSize, y / Constants.TerrainPatchSize, serialised); });
+                delegate(IClientAPI controller) 
+                    { controller.SendLayerData(
+                        x / Constants.TerrainPatchSize, y / Constants.TerrainPatchSize, serialised); 
+                    }
+            );
         }
 
         private void client_OnModifyTerrain(float height, float seconds, byte size, byte action, float north, float west,