assert DestinationExists when using overwrite=False

Author: tfeldmann

fs/base.py

@@ -1161,6 +1161,9 @@ def move(self, src_path, dst_path, overwrite=False, preserve_time=False):
             raise errors.DestinationExists(dst_path)
         if self.getinfo(src_path).is_dir:
             raise errors.FileExpected(src_path)
+        if normpath(src_path) == normpath(dst_path):
+            # early exit when moving a file onto itself
+            return
         if self.getmeta().get("supports_rename", False):
             try:
                 src_sys_path = self.getsyspath(src_path)

fs/osfs.py

@@ -409,7 +409,7 @@ def _check_copy(self, src_path, dst_path, overwrite=False):
         if self.gettype(src_path) is not ResourceType.file:
             raise errors.FileExpected(src_path)
         # check dst_path does not exist if we are not overwriting
-        if not overwrite and _src_path != _dst_path and self.exists(_dst_path):
+        if not overwrite and self.exists(_dst_path):
             raise errors.DestinationExists(dst_path)
         # check parent dir of _dst_path exists and is a directory
         if self.gettype(dirname(dst_path)) is not ResourceType.directory:

fs/test.py

@@ -1816,23 +1816,35 @@ def test_move_file_onto_itself(self):
         self.fs.move("file.txt", "file.txt", overwrite=True)
         self.assert_text("file.txt", "Hello")
 
+        with self.assertRaises(errors.DestinationExists):
+            self.fs.move("file.txt", "file.txt", overwrite=False)
+
     def test_move_file_onto_itself_relpath(self):
         subdir = self.fs.makedir("sub")
         subdir.writetext("file.txt", "Hello")
         self.fs.move("sub/file.txt", "sub/../sub/file.txt", overwrite=True)
         self.assert_text("sub/file.txt", "Hello")
 
+        with self.assertRaises(errors.DestinationExists):
+            self.fs.move("sub/file.txt", "sub/../sub/file.txt", overwrite=False)
+
     def test_copy_file_onto_itself(self):
         self.fs.writetext("file.txt", "Hello")
         self.fs.copy("file.txt", "file.txt", overwrite=True)
         self.assert_text("file.txt", "Hello")
 
+        with self.assertRaises(errors.DestinationExists):
+            self.fs.copy("file.txt", "file.txt", overwrite=False)
+
     def test_copy_file_onto_itself_relpath(self):
         subdir = self.fs.makedir("sub")
         subdir.writetext("file.txt", "Hello")
         self.fs.copy("sub/file.txt", "sub/../sub/file.txt", overwrite=True)
         self.assert_text("sub/file.txt", "Hello")
 
+        with self.assertRaises(errors.DestinationExists):
+            self.fs.copy("sub/file.txt", "sub/../sub/file.txt", overwrite=False)
+
     def test_copydir(self):
         self.fs.makedirs("foo/bar/baz/egg")
         self.fs.writetext("foo/bar/foofoo.txt", "Hello")