The image upload dialog used to have proper tab order so one could, for example on OS X, do the following:
- Press ⌘G
- Press Tab to focus file upload button, then ␣ (Space)
- File selection window opens; select file
- Press Tab to focus upload button, then ␣ to upload
This had the benefit of not having to use the mouse at all to upload an image.
Now, when I press Tab after the dialog opens, control is still on the editor underneath the dialog. Muscle memory just made me submit the post because I tabbed to the "Post Answer" button and clicked it with Space, all while the dialog was overlaying the actual page.
I consider this a regression, as focus should be on the active dialog to make this easier accessible for keyboard-only users.