rebase --root conflicts with --committer-date-is-author-date

============ version:

git version 2.1.4 Linux wolke-w520 3.19.3-towo.1-siduction-amd64 #1 SMP PREEMPT siduction 3.19-9 (2015-03-26) x86_64 GNU/Linux ============ summary:

if i do `git rebase --committer-date-is-author-date --root', the committer date is set to now, instead of set to the author date. when rebasing onto the first commit, it works perfectly well. ============ reproduce:

set -x cd mkdir test cd test git init echo line >> a; git add a; git commit -m 'jan1' --date '2015-01-01' echo line >> a; git add a; git commit -m 'jan2' --date '2015-01-02' echo line >> a; git add a; git commit -m 'jan3' --date '2015-01-03' git log --format=format:%s-%cD-%aD%n git rebase --committer-date-is-author-date HEAD^^ git log --format=format:%s-%cD-%aD%n git rebase --committer-date-is-author-date --root git log --format=format:%s-%cD-%aD%n git rebase --committer-date-is-author-date HEAD^^ git log --format=format:%s-%cD-%aD%n git rebase --committer-date-is-author-date --root git log --format=format:%s-%cD-%aD%n ============ expected:

jan3-Sat, 03 Jan 2015 13:28:06 -0500-Sat, 3 Jan 2015 13:28:06 -0500 jan2-Sat, 02 Jan 2015 13:28:06 -0500-Fri, 2 Jan 2015 13:28:06 -0500 jan1-Sat, 01 Jan 2015 13:28:06 -0500-Thu, 1 Jan 2015 13:28:06 -0500 ============ actual:

jan3-Sat, 11 Apr 2015 14:28:06 -0400-Sat, 3 Jan 2015 13:28:06 -0500 jan2-Sat, 11 Apr 2015 14:28:06 -0400-Fri, 2 Jan 2015 13:28:06 -0500 jan1-Sat, 11 Apr 2015 14:28:06 -0400-Thu, 1 Jan 2015 13:28:06 -0500

{full output: http://pastie.org/10086950} ============ sorry if dupe/wrong-venue/poorly-formatted/incomprehensible. i tried.