Dojo HowTo -- Rolling Patches (video tute)

When you are doing a patch you only want to change the things that directly relate to the issue. Whitespace (and formatting) cleanup has nothing to do with most functional code changes. If you went through and cleaned up all of the whitespace in the file at the same time you changed some code, the patch could be very big but only have one substantive change in it. That makes is hard for people reviewing to find the meat of your patch, meaning it is less likely to get reviewed and frankly, it's just annoying. :) Another thing to keep in mind is that if your text editor is set up to automatically remove whitespace for you, then you need to turn that setting off before you do your patches or you could create a mess without intending to.

A great idea is to do the patch with just the code changes you need and submit that to your issue. Then you can go back and do a separate whitespace/formatting cleanup patch where all you do is clean up whitespace problems and put that in a new issue. I know it may sound kinda silly at first but when folks are trying to review tons of code in a day, keeping the code changes discrete to each particular issue you are addressing makes everything more efficient in the end.

Also, whitespace cleanup and general code formatting cleanup patches are a great way to dip your toe into patch rolling without being freaked about the code itself. The coder module is a great tool for even someone new to help with code cleanup. And, of course, you should also read the coding standards in the handbook too if you want to help out with cleanup.