image-dired-rotate-original-ask-before-overwrite

image-dired-rotate-original-ask-before-overwrite is a variable defined in `image-dired.el'.
Its value is

t

Documentation:
Confirm overwrite of original file after rotate operation.
If non-nil, ask user for confirmation before overwriting the
original file with `image-dired-temp-rotate-image-file'.

You can customize this variable.