git pretty format: "%+b" not working with "%w" in front of it?

I have the following log:

$ git log

commit 7ffb909bb8f38607e3d6d9f3504a66ca978f0ac2
Author: Robert Dailey <robert@ziosk.com>
Date:   Mon Dec 12 11:01:00 2016 -0600

    Add initial skeleton files & a few interfaces for new kizi/sc16 stuff

    This is still FAR from complete....

I want to generate changelogs, using github markdown list format. I tried doing that using this command:

$ git log --pretty=format:"* %s%n%w(100,2,2)%+b"

However, the 2nd newline is not inserted:

* Add initial skeleton files & a few interfaces for new kizi/sc16 stuff
   This is still FAR from complete....

The format I'm expecting is:

* Add initial skeleton files & a few interfaces for new kizi/sc16 stuff

  This is still FAR from complete....

This seems to work, but I do not get the 2-space indentation required to continue text on the current list item:

$ git log --pretty=format:"* %s%n%+b"

* Add initial skeleton files & a few interfaces for new kizi/sc16 stuff

This is still FAR from complete....

So why isn't it working when I use %w before the %+b? Am I doing something wrong? Note I'm using git version 2.10 on Windows through Git Bash.

On Wed, Mar 15, 2017 at 09:08:10AM -0500, Robert Dailey wrote:

Hmm. I think the leading newline is added, but it gets eaten by the wrapping code. If I run your example in a debugger, we enter strbuf_add_wrapped_text() with:

  buf = "* the subject line\n"
  text = "\nthe body text"
  indent1=2, indent2=2, width=100

Which looks right. But the wrapping code seems to treat blank lines oddly. I can't quite figure out what it's _trying_ to do, but if there's one blank line, it gets converted into a space (and thus the weird three-space indent you see). But if there are two, they are both preserved!

So I think the line-wrapping code is simply buggy, and you are not doing anything wrong. But maybe I am missing some subtle case.

-Peff