Here is the history of a question I tried to edit.
I first clicked edit on revision 4. Then I added the python-2.x tag because it was correct. I then saved it.
What happened then? My edit... didn't do anything at all!
What did I break? What happened?
It appears I must zoom out a bit to clear some confusion:
To summarize: my intent was to roll back the change made to the body text by the suggested edit while preserving the change made to the tags. While the tag change was kept, the body changes were not rolled back!