Merge with git 1.9.2

Hello,
I tried to build msysgit 1.9.2 and it seemed to be very easy. I did "git merge v1.9.2" and there was one trivial merge conflict.  The test suite is ok until 7407.  There was a fail in 7407, but it did not reproduce on subsequent runs.  But while I was at it, I noticed that part of @dscho's workaround there is not (no longer?) necessary.

(The only CR problem seems to come from running echo from within git; I guess it runs cmd.exe echo, not sh echo.)

Back to original subject: what is the right way to create v1.9.2.msysgit?

I also tried `git rebase -i --autosquash --onto v1.9.2 v1.9.0`
I took ages and created script that contained ~5800 commits; does that make sense?
Or should the rebase be called with --preserve-merges?

I'll be grateful for any explanations, though I suspect this may not be the best place for this discussion.
Stepan