Fix for issue 10684: Folders get deleted when trying to change case with shutil.move (case insensitive file systems only)

Lib/shutil.py

@@ -260,12 +260,18 @@ def move(src, dst):
     """
     real_dst = dst
     if os.path.isdir(dst):
+        if _samefile(src, dst):
+            # We might be on a case insensitive filesystem,
+            # perform the rename anyway.
+            os.rename(src, dst)
+            return
+
         real_dst = os.path.join(dst, _basename(src))
         if os.path.exists(real_dst):
             raise Error("Destination path '%s' already exists" % real_dst)
     try:
         os.rename(src, real_dst)
-    except OSError:
+    except OSError as exc:
         if os.path.isdir(src):
             if _destinsrc(src, dst):
                 raise Error("Cannot move a directory '%s' into itself '%s'." % (src, dst))

Lib/test/test_shutil.py

@@ -522,6 +522,24 @@ class TestCopyFile(unittest.TestCase):
         self.assertTrue(srcfile._exited_with[0] is None)
         self.assertTrue(srcfile._raised)
 
+    def test_move_dir_caseinsensitive(self):
+        # Renames a folder to the same name
+        # but a different case.
+
+        self.src_dir = tempfile.mkdtemp()
+        dst_dir = os.path.join(
+                os.path.dirname(self.src_dir),
+                os.path.basename(self.src_dir).upper())
+        self.assertNotEqual(self.src_dir, dst_dir)
+
+        try:
+            shutil.move(self.src_dir, dst_dir)
+            self.assertTrue(os.path.isdir(dst_dir))
+        finally:
+            if os.path.exists(dst_dir):
+                os.rmdir(dst_dir)
+
+
 
 def test_main():
     support.run_unittest(TestShutil, TestMove, TestCopyFile)

Misc/NEWS

@@ -66,6 +66,10 @@ Core and Builtins
 Library
 -------
 
+- Issue #10684: shutil.move used to delete a folder on case insensitive
+  filesystems when the source and destination name where the same except
+  for the case.
+
 - Issue #11277: mmap.mmap() calls fcntl(fd, F_FULLFSYNC) on Mac OS X to get
   around a mmap bug with sparse files. Patch written by Steffen Daode Nurpmeso.