When dealing with binary files on Git repositories, we often would like to be able to diff and see changes on such files. However, git diff is not very helpful when working with non-textual files.

Fortunately, it's relatively simple to help git show us meaningful diffs for these files. We only need to add some lines to our configuration file and have the right tools installed.

If you are collaborating with a project that uses email as a patch exchange method, you will probably need to send many versions of your patches to public mailing lists. To aid in distinguishing the new from the old, we use version numbers on the email subjects; for example

[PATCH v2 0/9] wilink: add device tree support

indicates that these 9 patches are part of the second iteration of the patch series.

Git 1.8.2 added a new option, --reroll-count N, that lets us introduce this number automatically when using format-patch and send-email. This is mostly equivalent to passing --subject="PATCH vN" on older Git versions, except that --reroll-count will also alter the patch filenames.

As a kernel contributor, I often like to build test my series of patches to make sure they are bisectable - that is, to make sure the code still builds (and hopefully runs) after each one of my changes. However, I did not find any easy and automatic way to do this, so I ended up writing a very simple implementation of it in sh, which I will show you here.

First, you will need to create a shell script and put it somewhere on your $PATH; I used ~/bin/git-build-test. Make sure you chmod +x it as well so we can then run it.

DKIM (DomainKeys Identified Mail, not to be confused with DomainKeys) is a method for associating a domain name to an email message, allowing a person or organization to claim some responsibility for the message. By using a digital signature, the recipient can check if an email actually originated from a certain domain; this can be useful to prevent phishing and spam.

If you are running an exim4 instance as a SMTP server for your domain, you can configure DKIM signing on your outgoing email in four easy steps. This guide is based on Debian, but it should not vary much if you are using some other distribution.

I found the --autosquash argument of git rebase --interactive to be very useful for my workflow. I usually keep a development branch, where I commit early and often. This means I'm usually left with a commit containing the actual feature, and then some smaller commits fixing bugs and other issues, that I later squash together using git rebase --interactive

Starting on 1.7.4, Git has two flags on commit that can help people who work this way: --fixup and --squash. They let you mark a commit as fixing up another one, and will automatically sort the commits on rebase --interactive as well as change the action to fixup or squash, respectively.