commit 65c92c5870944b972a879031abd4c20c4f0d7981
author Bruno P. Kinoshita <kinow@users.noreply.github.com> Wed Nov 27 17:49:37 2019 +1300
committer Giampaolo Rodola <g.rodola@gmail.com> Wed Nov 27 12:49:37 2019 +0800
tree 1176ca68f6d6bb600e69f4a6333d8d9ab4d22380
parent a9c86f5e1afa2487524b1947153953b583714d62

[3.8] bpo-38688, shutil.copytree: consume iterator and create list of entries to prevent infinite recursion (GH-17397)

(cherry picked from commit 9bbcbc9f6dfe1368fe7330b117707f828e6a2c18)

Co-authored-by: Bruno P. Kinoshita <kinow@users.noreply.github.com>

Lib/shutil.py

diff --git a/Lib/shutil.py b/Lib/shutil.py
index 1e89256..755ce39 100644
--- a/Lib/shutil.py
+++ b/Lib/shutil.py
@@ -442,7 +442,7 @@
 def _copytree(entries, src, dst, symlinks, ignore, copy_function,
               ignore_dangling_symlinks, dirs_exist_ok=False):
     if ignore is not None:
-        ignored_names = ignore(src, set(os.listdir(src)))
+        ignored_names = ignore(src, {x.name for x in entries})
     else:
         ignored_names = set()
 
@@ -543,11 +543,12 @@
 
     """
     sys.audit("shutil.copytree", src, dst)
-    with os.scandir(src) as entries:
-        return _copytree(entries=entries, src=src, dst=dst, symlinks=symlinks,
-                         ignore=ignore, copy_function=copy_function,
-                         ignore_dangling_symlinks=ignore_dangling_symlinks,
-                         dirs_exist_ok=dirs_exist_ok)
+    with os.scandir(src) as itr:
+        entries = list(itr)
+    return _copytree(entries=entries, src=src, dst=dst, symlinks=symlinks,
+                     ignore=ignore, copy_function=copy_function,
+                     ignore_dangling_symlinks=ignore_dangling_symlinks,
+                     dirs_exist_ok=dirs_exist_ok)
 
 if hasattr(os.stat_result, 'st_file_attributes'):
     # Special handling for directory junctions to make them behave like

Lib/test/test_shutil.py

diff --git a/Lib/test/test_shutil.py b/Lib/test/test_shutil.py
index b98e7dc..286e333 100644
--- a/Lib/test/test_shutil.py
+++ b/Lib/test/test_shutil.py
@@ -1605,6 +1605,18 @@
         rv = shutil.copytree(src_dir, dst_dir)
         self.assertEqual(['foo'], os.listdir(rv))
 
+    def test_copytree_subdirectory(self):
+        # copytree where dst is a subdirectory of src, see Issue 38688
+        base_dir = self.mkdtemp()
+        self.addCleanup(shutil.rmtree, base_dir, ignore_errors=True)
+        src_dir = os.path.join(base_dir, "t", "pg")
+        dst_dir = os.path.join(src_dir, "somevendor", "1.0")
+        os.makedirs(src_dir)
+        src = os.path.join(src_dir, 'pol')
+        write_file(src, 'pol')
+        rv = shutil.copytree(src_dir, dst_dir)
+        self.assertEqual(['pol'], os.listdir(rv))
+
 
 class TestWhich(unittest.TestCase):