TYPO3 Core

It does not seem to affect 7.6.x, just 8.7.13 and 9.3 (latest master).

Confirmed with the following procedure:

Prerequisites¶

- TYPO3 with a custom workspace

Procedure¶

1) LIVE workspace > Go to page module or list module
2) create a new content element (e.g. header), edit it (e.g. name it "test") and click on save button (NOT save and close just save )
3) Immediately go to your custom workspace using the header dropdown
4) Go to list module

Result¶

You will find two "test" elements,
- the one you created on LIVE
- another one created on that workspace (if you go hover its icon, the tooltip reads "id=XXX New Element!") see also attached file

EditDocumentController is reloaded with the same NEW... identifier that gets persisted by DataHandler again.
NavigationContainer.ts triggers contentWindow.location.reload which enforces the form data to be resend and persisted again.

• the optional information in modules whether reload is required - in terms of FormEngine that would be required
• the optional information which URL to load (the current "canonical URL" of some backend module content)
• NavigationContainer.ts using the information above (if available) instead of using contentWindow.location.reload

I do think this is fixed now?

this has been fixed in v11 afaiks: editDocumentController now reloads after save, so the post isn't executed again when switching workspaces anymore.