Issue #6050: Don't fail extracting a directory from a zipfile if

the directory already exists.

Lib/test/test_zipfile.py

@@ -1023,6 +1023,11 @@ class TestWithDirectory(unittest.TestCase):
         self.assertTrue(os.path.isdir(os.path.join(TESTFN2, "a", "b")))
         self.assertTrue(os.path.exists(os.path.join(TESTFN2, "a", "b", "c")))
 
+    def test_bug_6050(self):
+        # Extraction should succeed if directories already exist
+        os.mkdir(os.path.join(TESTFN2, "a"))
+        self.testExtractDir()
+
     def testStoreDir(self):
         os.mkdir(os.path.join(TESTFN2, "x"))
         zipf = zipfile.ZipFile(TESTFN, "w")

Lib/zipfile.py

@@ -971,7 +971,8 @@ class ZipFile:
             os.makedirs(upperdirs)
 
         if member.filename[-1] == '/':
-            os.mkdir(targetpath)
+            if not os.path.isdir(targetpath):
+                os.mkdir(targetpath)
             return targetpath
 
         source = self.open(member, pwd=pwd)

Misc/NEWS

@@ -302,6 +302,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #6050: Don't fail extracting a directory from a zipfile if
+  the directory already exists.
+
 - Issue #5311: bdist_msi can now build packages that do not depend on a
   specific Python version.