Re: [PATCH v2 0/4] fix "rebase -i --root" corrupting root commit

> This is a re-roll of [1] which fixes sequencer bugs resulting in commit
> object corruption when "rebase -i --root" swaps in a new commit as root.
> Unfortunately, those bugs made it into v2.18.0 and have already
> corrupted at least one repository (a local project of mine). Patches 3/4
> and 4/4 are new.
> 
> v1 fixed these bugs:
> 
> * trailing garbage on the commit's "author" header
> 
> * extra trailing digit on "author" header's timezone (caused by two
>   separate bugs)
> 
> v2 fixes those same bugs, plus:
> 
> * eliminates a bogus "@" prepended to the "author" header timestamp
>   which renders the header corrupt
> 
> * takes care to validate information coming from
>   "rebase-merge/author-script" before incorporating it into the "author"
>   header since that file may be hand-edited, and bogus hand-edited
>   values could corrupt the commit object.