bpo-36991: Fix incorrect exception escaping ZipFile.extract() (GH-13632)

miss-islington · berkerpeksag · web-flow · commit 717cc61ed103 · 2019-09-12T07:33:53.000-07:00
(cherry picked from commit 2f1b857) Co-authored-by: Berker Peksag <berker.peksag@gmail.com>
diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
@@ -9,6 +9,7 @@
 import sys
 import time
 import unittest
+import unittest.mock as mock
 import zipfile
 
 
@@ -1739,6 +1740,16 @@ def test_seek_tell(self):
                 fp.seek(0, os.SEEK_SET)
                 self.assertEqual(fp.tell(), 0)
 
+    @requires_bz2
+    def test_decompress_without_3rd_party_library(self):
+        data = b'PK\x05\x06\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
+        zip_file = io.BytesIO(data)
+        with zipfile.ZipFile(zip_file, 'w', compression=zipfile.ZIP_BZIP2) as zf:
+            zf.writestr('a.txt', b'a')
+        with mock.patch('zipfile.bz2', None):
+            with zipfile.ZipFile(zip_file) as zf:
+                self.assertRaises(RuntimeError, zf.extract, 'a.txt')
+
     def tearDown(self):
         unlink(TESTFN)
         unlink(TESTFN2)
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
@@ -703,6 +703,7 @@ def _get_compressor(compress_type, compresslevel=None):
 
 
 def _get_decompressor(compress_type):
+    _check_compression(compress_type)
     if compress_type == ZIP_STORED:
         return None
     elif compress_type == ZIP_DEFLATED:
diff --git a/Misc/NEWS.d/next/Library/2019-09-12-14-52-38.bpo-36991.1OcSm8.rst b/Misc/NEWS.d/next/Library/2019-09-12-14-52-38.bpo-36991.1OcSm8.rst
@@ -0,0 +1,2 @@
+Fixes a potential incorrect AttributeError exception escaping
+ZipFile.extract() in some unsupported input error situations.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+Fixes a potential incorrect AttributeError exception escaping`
	`2`	`+ZipFile.extract() in some unsupported input error situations.`