gh-114959: tarfile: do not ignore errors when extract a directory on top of a file (GH-114960)

Also, add tests common to tarfile and zipfile.

1 files changed, 155 insertions, 0 deletions

diff --git a/Lib/test/archiver_tests.py b/Lib/test/archiver_tests.py
new file mode 100644
index 00000000000..1a4bbb9e570
--- /dev/null
+++ b/Lib/test/archiver_tests.py
@@ -0,0 +1,155 @@
+"""Tests common to tarfile and zipfile."""
+
+import os
+import sys
+
+from test.support import os_helper
+
+class OverwriteTests:
+
+    def setUp(self):
+        os.makedirs(self.testdir)
+        self.addCleanup(os_helper.rmtree, self.testdir)
+
+    def create_file(self, path, content=b''):
+        with open(path, 'wb') as f:
+            f.write(content)
+
+    def open(self, path):
+        raise NotImplementedError
+
+    def extractall(self, ar):
+        raise NotImplementedError
+
+
+    def test_overwrite_file_as_file(self):
+        target = os.path.join(self.testdir, 'test')
+        self.create_file(target, b'content')
+        with self.open(self.ar_with_file) as ar:
+            self.extractall(ar)
+        self.assertTrue(os.path.isfile(target))
+        with open(target, 'rb') as f:
+            self.assertEqual(f.read(), b'newcontent')
+
+    def test_overwrite_dir_as_dir(self):
+        target = os.path.join(self.testdir, 'test')
+        os.mkdir(target)
+        with self.open(self.ar_with_dir) as ar:
+            self.extractall(ar)
+        self.assertTrue(os.path.isdir(target))
+
+    def test_overwrite_dir_as_implicit_dir(self):
+        target = os.path.join(self.testdir, 'test')
+        os.mkdir(target)
+        with self.open(self.ar_with_implicit_dir) as ar:
+            self.extractall(ar)
+        self.assertTrue(os.path.isdir(target))
+        self.assertTrue(os.path.isfile(os.path.join(target, 'file')))
+        with open(os.path.join(target, 'file'), 'rb') as f:
+            self.assertEqual(f.read(), b'newcontent')
+
+    def test_overwrite_dir_as_file(self):
+        target = os.path.join(self.testdir, 'test')
+        os.mkdir(target)
+        with self.open(self.ar_with_file) as ar:
+            with self.assertRaises(PermissionError if sys.platform == 'win32'
+                                   else IsADirectoryError):
+                self.extractall(ar)
+        self.assertTrue(os.path.isdir(target))
+
+    def test_overwrite_file_as_dir(self):
+        target = os.path.join(self.testdir, 'test')
+        self.create_file(target, b'content')
+        with self.open(self.ar_with_dir) as ar:
+            with self.assertRaises(FileExistsError):
+                self.extractall(ar)
+        self.assertTrue(os.path.isfile(target))
+        with open(target, 'rb') as f:
+            self.assertEqual(f.read(), b'content')
+
+    def test_overwrite_file_as_implicit_dir(self):
+        target = os.path.join(self.testdir, 'test')
+        self.create_file(target, b'content')
+        with self.open(self.ar_with_implicit_dir) as ar:
+            with self.assertRaises(FileNotFoundError if sys.platform == 'win32'
+                                   else NotADirectoryError):
+                self.extractall(ar)
+        self.assertTrue(os.path.isfile(target))
+        with open(target, 'rb') as f:
+            self.assertEqual(f.read(), b'content')
+
+    @os_helper.skip_unless_symlink
+    def test_overwrite_file_symlink_as_file(self):
+        # XXX: It is potential security vulnerability.
+        target = os.path.join(self.testdir, 'test')
+        target2 = os.path.join(self.testdir, 'test2')
+        self.create_file(target2, b'content')
+        os.symlink('test2', target)
+        with self.open(self.ar_with_file) as ar:
+            self.extractall(ar)
+        self.assertTrue(os.path.islink(target))
+        self.assertTrue(os.path.isfile(target2))
+        with open(target2, 'rb') as f:
+            self.assertEqual(f.read(), b'newcontent')
+
+    @os_helper.skip_unless_symlink
+    def test_overwrite_broken_file_symlink_as_file(self):
+        # XXX: It is potential security vulnerability.
+        target = os.path.join(self.testdir, 'test')
+        target2 = os.path.join(self.testdir, 'test2')
+        os.symlink('test2', target)
+        with self.open(self.ar_with_file) as ar:
+            self.extractall(ar)
+        self.assertTrue(os.path.islink(target))
+        self.assertTrue(os.path.isfile(target2))
+        with open(target2, 'rb') as f:
+            self.assertEqual(f.read(), b'newcontent')
+
+    @os_helper.skip_unless_symlink
+    def test_overwrite_dir_symlink_as_dir(self):
+        # XXX: It is potential security vulnerability.
+        target = os.path.join(self.testdir, 'test')
+        target2 = os.path.join(self.testdir, 'test2')
+        os.mkdir(target2)
+        os.symlink('test2', target, target_is_directory=True)
+        with self.open(self.ar_with_dir) as ar:
+            self.extractall(ar)
+        self.assertTrue(os.path.islink(target))
+        self.assertTrue(os.path.isdir(target2))
+
+    @os_helper.skip_unless_symlink
+    def test_overwrite_dir_symlink_as_implicit_dir(self):
+        # XXX: It is potential security vulnerability.
+        target = os.path.join(self.testdir, 'test')
+        target2 = os.path.join(self.testdir, 'test2')
+        os.mkdir(target2)
+        os.symlink('test2', target, target_is_directory=True)
+        with self.open(self.ar_with_implicit_dir) as ar:
+            self.extractall(ar)
+        self.assertTrue(os.path.islink(target))
+        self.assertTrue(os.path.isdir(target2))
+        self.assertTrue(os.path.isfile(os.path.join(target2, 'file')))
+        with open(os.path.join(target2, 'file'), 'rb') as f:
+            self.assertEqual(f.read(), b'newcontent')
+
+    @os_helper.skip_unless_symlink
+    def test_overwrite_broken_dir_symlink_as_dir(self):
+        target = os.path.join(self.testdir, 'test')
+        target2 = os.path.join(self.testdir, 'test2')
+        os.symlink('test2', target, target_is_directory=True)
+        with self.open(self.ar_with_dir) as ar:
+            with self.assertRaises(FileExistsError):
+                self.extractall(ar)
+        self.assertTrue(os.path.islink(target))
+        self.assertFalse(os.path.exists(target2))
+
+    @os_helper.skip_unless_symlink
+    def test_overwrite_broken_dir_symlink_as_implicit_dir(self):
+        target = os.path.join(self.testdir, 'test')
+        target2 = os.path.join(self.testdir, 'test2')
+        os.symlink('test2', target, target_is_directory=True)
+        with self.open(self.ar_with_implicit_dir) as ar:
+            with self.assertRaises(FileExistsError):
+                self.extractall(ar)
+        self.assertTrue(os.path.islink(target))
+        self.assertFalse(os.path.exists(target2))