Cannot "cancel" adding a gadget on a dashboard, or removing a gadget or editing the parameters of a gadget

The issue is that hitting the cancel button in the dashboard editor doesn't actually cancel these actions. E.g. a removed gadget will remain removed even after hitting cancel button.
To reproduce:

1. go to a dashboard, edit it (Edit -> Inline Form)
2. remove a gadget, confirm the button that asks whether you are sure you want to remove the gadget
3. hit the cancel button in the bottom of the page. The page will come back to view mode, but the removed gadget will remain removed.

Same if, in step 2, instead of remove, there is a gadget add or the edit of a gadget parameters.