From a9e1c25968ae42e79bbe3d6a6da58c0d76f3ab25 Mon Sep 17 00:00:00 2001
From: Berk <12572227+par274@users.noreply.github.com>
Date: Mon, 28 Sep 2026 04:43:05 +0300
Subject: [PATCH] [Ampr] Fix PakDirectoryTracker to handle multiple directories
 with the same name (#925)

---
 src/SharpEmu.Libs/Ampr/PakDirectoryTracker.cs   | 17 ++++++++++++++++-
 .../Ampr/PakDirectoryTrackerTests.cs            | 17 +++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/SharpEmu.Libs/Ampr/PakDirectoryTracker.cs b/src/SharpEmu.Libs/Ampr/PakDirectoryTracker.cs
index 6b82a42..e5233f0 100644
--- a/src/SharpEmu.Libs/Ampr/PakDirectoryTracker.cs
+++ b/src/SharpEmu.Libs/Ampr/PakDirectoryTracker.cs
@@ -60,10 +60,19 @@ internal static class PakDirectoryTracker
             // related assets, and the guest streams them with locality, so disambiguate collisions
             // by choosing the unconsumed match nearest the running read cursor.
             DirectoryEntry? best = null;
+            DirectoryEntry? uniqueMatch = null;
+            var matchCount = 0;
             var bestDistance = ulong.MaxValue;
             foreach (var entry in entries)
             {
-                if (entry.Consumed || entry.FileLen != requestedSize)
+                if (entry.FileLen != requestedSize)
+                {
+                    continue;
+                }
+
+                uniqueMatch = entry;
+                matchCount++;
+                if (entry.Consumed)
                 {
                     continue;
                 }
@@ -90,6 +99,12 @@ internal static class PakDirectoryTracker
 
                 return best.FilePos;
             }
+
+            // A unique archive member may be opened again after its first read.
+            if (matchCount == 1)
+            {
+                return uniqueMatch!.FilePos;
+            }
         }
 
         return state.NextOffset;
diff --git a/tests/SharpEmu.Libs.Tests/Ampr/PakDirectoryTrackerTests.cs b/tests/SharpEmu.Libs.Tests/Ampr/PakDirectoryTrackerTests.cs
index d07f42a..3b79e30 100644
--- a/tests/SharpEmu.Libs.Tests/Ampr/PakDirectoryTrackerTests.cs
+++ b/tests/SharpEmu.Libs.Tests/Ampr/PakDirectoryTrackerTests.cs
@@ -72,6 +72,23 @@ public sealed class PakDirectoryTrackerTests
         Assert.Equal(0x1000UL + (runLen * 2), third);
     }
 
+    [Fact]
+    public void ResolveSequentialOffset_UniqueEntryCanBeReadAgain()
+    {
+        const uint fileId = 0x5AA5_0003;
+        const uint size = 15903;
+        var memory = new FakeCpuMemory(0x1_0000_0000, 0x1000);
+        var ctx = new CpuContext(memory, Generation.Gen5);
+        LoadDirectory(ctx, fileId, memory, 0x1_0000_0000, dirFileOffset: 0x400, new[]
+        {
+            new PakEntry("bots/characters.txt", FilePos: 0xF81CF, FileLen: size),
+        });
+
+        Assert.Equal(0xF81CFUL, PakDirectoryTracker.ResolveSequentialOffset(fileId, size));
+        PakDirectoryTracker.OnReadCompleted(ctx, fileId, destination: 0x1_0000_0000, fileOffset: 0xF81CF, bytesRead: size);
+        Assert.Equal(0xF81CFUL, PakDirectoryTracker.ResolveSequentialOffset(fileId, size));
+    }
+
     // Feeds the tracker a synthetic PACK header + directory table exactly as the AMPR read path does:
     // first the 12-byte header (which arms directory parsing), then the directory records themselves.
     private static void LoadDirectory(