• VSCode Version: 1.16.1
• OS Version: Windows 8.1

Steps to Reproduce:

1. In a html file, type (not copy) <span>test
2. Undo to before step 1
3. Redo

Now you cannot redo the typing of test or any edits after that point, as the auto close overwrote the undo/redo history.

Alternate steps:

1. Delete an opening tag not immediately followed by its closing tag; e.g. delete the <span> of <span>test</span>
2. Undo your deletion

Reproduces without extensions: Yes

Expected behavior:

VSCode does not perform any new automatic formatting on undo/redo.