For a better code reviewability, don't combine refactoring changes and fix changes into a single commit.
If it's a very small refactoring change, it's completely fine, we can combine together. Otherwise, it's going to be difficult for the reviewer to read the code and understand it. The Reviewer has to change the context from refactoring to an actual fix and vice versa, and in the process, we tend to ignore the actual fix code and that leads a problem again!
Let me point to a first resource which I found when googled it about this subject.
http://jakegoulding.com/blog/2012/11/04/refactor-and-make-changes-in-different-commits/
If it's a very small refactoring change, it's completely fine, we can combine together. Otherwise, it's going to be difficult for the reviewer to read the code and understand it. The Reviewer has to change the context from refactoring to an actual fix and vice versa, and in the process, we tend to ignore the actual fix code and that leads a problem again!
Let me point to a first resource which I found when googled it about this subject.
http://jakegoulding.com/blog/2012/11/04/refactor-and-make-changes-in-different-commits/