From b2be8dec67c6b8d4568c42b417c2afce7ead2070 Mon Sep 17 00:00:00 2001
From: Dmitry Kovba <dkovba@apple.com>
Date: Thu, 9 Apr 2026 11:09:07 -0700
Subject: [PATCH] Remove the incorrect check for visited inodes (#659)
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Removes the incorrect check for visited inodes. Fixes the added failing
tests:

> ✘ Test sameAbsoluteSymlinkFollowedTwice() recorded an issue at
TestEXT4Reader+IO.swift:502:6: Caught error: symlink loop while
resolving: target/../symlink/file.txt
> ✘ Test sameAbsoluteSymlinkFollowedTwice() failed after 0.009 seconds
with 1 issue.

> ✘ Test sameRelativeSymlinkFollowedTwice() recorded an issue at
TestEXT4Reader+IO.swift:516:6: Caught error: symlink loop while
resolving: ../target/../symlink/file.txt
> ✘ Test sameRelativeSymlinkFollowedTwice() failed after 0.010 seconds
with 1 issue.
---
 .../ContainerizationEXT4/EXT4Reader+IO.swift  |  7 -----
 .../TestEXT4Reader+IO.swift                   | 28 +++++++++++++++++++
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/Sources/ContainerizationEXT4/EXT4Reader+IO.swift b/Sources/ContainerizationEXT4/EXT4Reader+IO.swift
index f9daf25c..c2c93641 100644
--- a/Sources/ContainerizationEXT4/EXT4Reader+IO.swift
+++ b/Sources/ContainerizationEXT4/EXT4Reader+IO.swift
@@ -281,7 +281,6 @@ extension EXT4.EXT4Reader {
         var parentStack: [EXT4.InodeNumber] = []  // Track parent chain for proper ".." handling
 
         var symlinkHops = 0
-        var visitedInodes = Set<EXT4.InodeNumber>()
 
         // Process components one at a time to handle symlinks in the middle of paths
         var componentIndex = 0
@@ -330,12 +329,6 @@ extension EXT4.EXT4Reader {
             // Check if child is a symlink
             let childInode = try getInode(number: child.1)
             if childInode.mode.isLink() && followSymlinks {
-                // Check for symlink loop
-                if visitedInodes.contains(child.1) {
-                    throw EXT4.PathIOError.symlinkLoop(FilePath(components.joined(separator: "/")).description)
-                }
-                visitedInodes.insert(child.1)
-
                 // Enforce max symlink depth
                 symlinkHops += 1
                 if symlinkHops > maxSymlinks {
diff --git a/Tests/ContainerizationEXT4Tests/TestEXT4Reader+IO.swift b/Tests/ContainerizationEXT4Tests/TestEXT4Reader+IO.swift
index d987d9a0..6023a2b7 100644
--- a/Tests/ContainerizationEXT4Tests/TestEXT4Reader+IO.swift
+++ b/Tests/ContainerizationEXT4Tests/TestEXT4Reader+IO.swift
@@ -499,6 +499,34 @@ struct EXT4PathIOTests {
         }
     }
 
+    @Test
+    func sameAbsoluteSymlinkFollowedTwice() throws {
+        let url = try buildFS { fmt in
+            try self.createDir(fmt, "/target")
+            try self.createFile(fmt, "/target/file.txt", "OK")
+            try self.createSymlink(fmt, "/symlink", "/target")
+        }
+        defer { try? FileManager.default.removeItem(at: url) }
+
+        let r = try openReader(url)
+        let data = try r.readFile(at: FilePath("/symlink/../symlink/file.txt"))
+        #expect(String(decoding: data, as: UTF8.self) == "OK")
+    }
+
+    @Test
+    func sameRelativeSymlinkFollowedTwice() throws {
+        let url = try buildFS { fmt in
+            try self.createDir(fmt, "/target")
+            try self.createFile(fmt, "/target/file.txt", "OK")
+            try self.createSymlink(fmt, "/symlink", "../target")
+        }
+        defer { try? FileManager.default.removeItem(at: url) }
+
+        let r = try openReader(url)
+        let data = try r.readFile(at: FilePath("/symlink/../symlink/file.txt"))
+        #expect(String(decoding: data, as: UTF8.self) == "OK")
+    }
+
     @Test
     func boundsCheckingForInvalidExtents() throws {
         // This test verifies that the reader properly validates extent addresses