P.s. Just to let you in on little secrets of us here's what most of us do:
$ git checkout <branch/tag>
$ vim <file> # Or eclipse, etc. Editing++
$ ant/maven/tests etc.
$ git diff --no-prefix > PATCH.file
Or if on svn:
$ svn diff > PATCH.file # From project's root directory.
This is also covered in the HowToContribute document, and should help you avoid creating bad prefixed patches in future!
Keep up the good work