fix(advanced-search): upstream polish — guard DoSearch drain, Yield in worker drain, drop dead ParseValue surface

Projects/UOContent/Engines/Advanced Search/AdvancedSearchGump.cs

@@ -8,6 +8,7 @@ using Server.Commands;
 using Server.Commands.Generic;
 using Server.Engines.Spawners;
 using Server.Gumps;
+using Server.Logging;
 using Server.Network;
 using Server.Saves;
 
@@ -28,6 +29,8 @@ public enum AdvancedSearchGumpOptions : long
 
 public class AdvancedSearchGump : Gump
 {
+    private static readonly ILogger _logger = LogFactory.GetLogger(typeof(AdvancedSearchGump));
+
     private const int MaxEntries = 18;
 
     private static int _threadId;
@@ -828,6 +831,13 @@ public class AdvancedSearchGump : Gump
                     // Send the gump on the main thread
                     Core.LoopContext.Post(() => Resend(from));
                 }
+                catch (Exception ex)
+                {
+                    // Never let a drain-phase failure escape unhandled on the ThreadPool
+                    // thread - that would terminate the process. The finally below still
+                    // restores autosave and releases the search guard.
+                    _logger.Warning(ex, "AdvancedSearch: search drain failed");
+                }
                 finally
                 {
                     AutoSave.SavesEnabled = (bool)state!;

Projects/UOContent/Engines/Advanced Search/AdvancedSearchThreadWorker.cs

@@ -118,8 +118,10 @@ public class AdvancedSearchThreadWorker
                 }
                 else
                 {
-                    // Queue is transiently empty but we're not paused yet; avoid a 100%-CPU busy-spin.
-                    Thread.SpinWait(1);
+                    // Queue is transiently empty but we're not paused yet; yield the core to
+                    // other runnable threads (e.g. the other still-filtering workers) instead
+                    // of busy-spinning.
+                    Thread.Yield();
                 }
             }
 

Projects/UOContent/Engines/Advanced Search/AdvancedSearchUtilities.cs

@@ -273,12 +273,6 @@ public static class AdvancedSearchUtilities
         return false;
     }
 
-    public static T ParseValue<T>(ReadOnlySpan<char> valuePart)
-    {
-        TryParseValue(valuePart, out T value);
-        return value;
-    }
-
     internal static bool TryParseValue<T>(ReadOnlySpan<char> valuePart, out T value)
     {
         // Special handling for boolean and hexadecimal values