Addresses Mantis #1688

Changes erroneous return value of llGetLinkname() to "" for nonexistent
prims. Corrects an issue where the root prim of a linked set, upon
delink, retains the part number 1.

OpenSim/Region/Environment/Scenes/InnerScene.cs

@@ -1432,7 +1432,7 @@ namespace OpenSim.Region.Environment.Scenes
                     // The link set has been completely torn down
                     // This is the case if you select a link set and delink
                     //
-                    parenPrim.RootPart.LinkNum = 1;
+                    parenPrim.RootPart.LinkNum = 0;
                     if (sendEvents)
                         parenPrim.TriggerScriptChangedEvent(Changed.LINK);
                 }

OpenSim/Region/ScriptEngine/Common/LSL_BuiltIn_Commands.cs

@@ -2813,7 +2813,7 @@ namespace OpenSim.Region.ScriptEngine.Common
             }
             else
             {
-                return LLUUID.Zero.ToString();
+                return "";
             }
         }
 

OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs

@@ -2699,7 +2699,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
             }
             else
             {
-                return LLUUID.Zero.ToString();
+                return "";
             }
         }