From 5b5536dd5fa435967e174f83902a85b643e3a502 Mon Sep 17 00:00:00 2001
From: lipengyu <lipengyu@kylinos.cn>
Date: Sat, 22 Aug 2026 11:11:39 +0800
Subject: [PATCH] gh-156210: Fix shutil.copytree() detection of dangling
 relative symlinks

---
 Lib/shutil.py                                 |  2 +-
 Lib/test/test_shutil.py                       | 29 +++++++++++++++++++
 ...-08-22-11-00-09.gh-issue-156210.IBtBw-.rst |  3 ++
 3 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Library/2026-08-22-11-00-09.gh-issue-156210.IBtBw-.rst

diff --git a/Lib/shutil.py b/Lib/shutil.py
index ab75ba9da8894b6..e17242b33a6eaff 100644
--- a/Lib/shutil.py
+++ b/Lib/shutil.py
@@ -593,7 +593,7 @@ def _copytree(entries, src, dst, symlinks, ignore, copy_function,
                     copystat(srcobj, dstname, follow_symlinks=not symlinks)
                 else:
                     # ignore dangling symlink if the flag is on
-                    if not os.path.exists(linkto) and ignore_dangling_symlinks:
+                    if not os.path.exists(srcname) and ignore_dangling_symlinks:
                         continue
                     # otherwise let the copy occur. copy2 will raise an error
                     if srcentry.is_dir():
diff --git a/Lib/test/test_shutil.py b/Lib/test/test_shutil.py
index 06ebdf9b68f20fc..941179d9471b261 100644
--- a/Lib/test/test_shutil.py
+++ b/Lib/test/test_shutil.py
@@ -1060,6 +1060,35 @@ def test_copytree_dangling_symlinks(self):
         shutil.copytree(src_dir, dst_dir, symlinks=True)
         self.assertIn('test.txt', os.listdir(dst_dir))
 
+    @os_helper.skip_unless_symlink
+    def test_copytree_valid_relative_symlink(self):
+        root_dir = self.mkdtemp()
+        src_dir = os.path.join(root_dir, 'source')
+        os.mkdir(src_dir)
+        create_file(os.path.join(src_dir, 'target'), 'abc')
+        os.symlink('target', os.path.join(src_dir, 'link'))
+
+        dst_dir = os.path.join(root_dir, 'destination')
+        with os_helper.change_cwd(root_dir):
+            shutil.copytree(src_dir, dst_dir, ignore_dangling_symlinks=True)
+        self.assertEqual(['link', 'target'], sorted(os.listdir(dst_dir)))
+        self.assertFalse(os.path.islink(os.path.join(dst_dir, 'link')))
+        self.assertEqual('abc', read_file(os.path.join(dst_dir, 'link')))
+
+    @os_helper.skip_unless_symlink
+    def test_copytree_dangling_relative_symlink(self):
+        root_dir = self.mkdtemp()
+        src_dir = os.path.join(root_dir, 'source')
+        os.mkdir(src_dir)
+        os.symlink('target', os.path.join(src_dir, 'link'))
+        create_file(os.path.join(root_dir, 'target'), 'abc')
+
+        dst_dir = os.path.join(root_dir, 'destination')
+        with os_helper.change_cwd(root_dir):
+            shutil.copytree(src_dir, dst_dir,
+                            ignore_dangling_symlinks=True)
+        self.assertEqual([], os.listdir(dst_dir))
+
     @os_helper.skip_unless_symlink
     def test_copytree_symlink_dir(self):
         src_dir = self.mkdtemp()
diff --git a/Misc/NEWS.d/next/Library/2026-08-22-11-00-09.gh-issue-156210.IBtBw-.rst b/Misc/NEWS.d/next/Library/2026-08-22-11-00-09.gh-issue-156210.IBtBw-.rst
new file mode 100644
index 000000000000000..0f36109e59ab04f
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-08-22-11-00-09.gh-issue-156210.IBtBw-.rst
@@ -0,0 +1,3 @@
+Fix :func:`shutil.copytree` to determine whether relative symbolic links are
+dangling based on their parent directory rather than the current working
+directory when ``ignore_dangling_symlinks`` is true.