Patch Bombing and Change Stashing

I ran across the term 'patch bombing' today, which could be defined as; "multiple application logic changes all rolled into a single source code commit", it's the opposite of an 'atomic change'

I found the term relevant to a background thought I've been pickling over lately....

It's not uncommon for me to be in the middle of adding a new feature when I run across a bit of crufty code that needs to be refactored. Which poses the problem; How do I do the refactoring with out mixing the change sets?

In the past I'd just make both changes and write one fat commit message explaining everything but I always thought this approach smelled bad. Then, Jay Fields blogged about 'using patch as subversion's stash' and turned me on to 'the power of git-stash'.

It turns out that Bazaar, which I'm using for my current project, doesn't directly support this operation either but Jay's patch-stashing approach works just as well for bzr as it does for svn.