svn: reverting to previous version

Question

I mistakenly committed the wrong change to file, for a simplified example's sake let's call it foo.txt:

foo.txt, rev 300 (correct):

 E = mc^2

foo.txt, rev 301 (incorrect):

 E = mc^3

How do I re-commit rev 300 to the next commit? If I update foo.txt to rev 300, I get the right file but its status is correct & doesn't require being committed.

NOTE: It's only foo.txt that I want to revert. The other revisions in rev 301 are important and I need to keep them.

Answer 1

svn merge -r301:300 foo.txt
svn commit -m 'revert foo.txt to 300'