A suggestion for an option added to the rotate plugin prompted me to implement it as it seemed trivial.
The suggestion can be found at:
I have added the patch to this post as well as the above mentioned forum thread.
Created attachment 11400 [details] [review]
Patch for adding option to restrict movement in y direction
Mass closure: This bug has been untouched for more than six years, and is not
obviously still valid. Please reopen this bug or file a new report if you continue to experience issues with current releases.