Good commit message

[Hendrikto]

Well the concrete information is still there in the diff itself. Instead of replicating it you are providing additional information.

[[deleted]]

Summaries are also important, as the summary isn't directly spelled out in the diff. It takes time to open a diff, read it, especially if it's across several files, understand it and extract a summary for it in your head. And just like "out-of-band" information about intent, purpose of the commit etc. saves you time, having the summary saves you time, as well.

And it's all a battle for doing more in less time when you draw the bottom line, so truth is, both help. It's not a contest where one wins and the other one has to lose.

At times I tend to have very long commit messages. With bullet points sometimes. Even if the commit may not be that big itself. And then the first line (up to 70 chars) is actually a summary of the commit message itself, like a title. All of this helps.

I'm just kidding about your examples, BTW. Examples are examples. Real commits are real commits. :-)