Unsave Data Confirmation appears even if the data has been changed

[firdouserp]

What you were expecting:

No Unsave Data Warning should appear on after Submitting the form via Save

What happened instead:

Edit a Post on demo, goto miscelaneous and add a backlink via SimpleformIterator. Click save, A Confirmation warning of losing unsave data appears. It should not appear.
Steps to reproduce:

Related code:

• Preferably, a CodeSandbox forked from https://codesandbox.io/s/github/marmelab/react-admin/tree/master/examples/simple
• A link to a GitHub repo with the minimal codebase to reproduce the issue
  You can reproduce the error via this sandbox
  https://codesandbox.io/s/smoosh-browser-q05kc?file=/src/comments/CommentEdit.js

insert short code snippets here

Other information:

Environment

• React-admin version:
• Last version that did not exhibit the issue (if applicable):
• React version:
• Browser:
• Stack trace (in case of a JS error):

[djhi]

Thanks for the report. This issue is already tracked with #5267 though