Re: Bug: rebase -i creates committer time inversions on 'reword'

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Apr 14, 2018, 13:11 UTC
Message-ID: <nycvar.QRO.7.76.6.1804141444060.234@ZVAVAG-6OXH6DA.rhebcr.pbec.zvpebfbsg.pbz>
In-Reply-To: <f56b84fa-9286-3a7b-fc5b-2307c9ff5b5e@philandanna.no-ip.org>

Hi,

On Sat, 14 Apr 2018, Phillip Wood wrote:

Show 16 quoted lines

> On 13/04/18 17:52, Johannes Sixt wrote:
> > 
> > I just noticed that all commits in a 70-commit branch have the same
> > committer timestamp. This is very unusual on Windows, where rebase -i of
> > such a long branch takes more than one second (but not more than 3 or
> > so thanks to the builtin nature of the command!).
> > 
> > And, in fact, if you mark some commits with 'reword' to delay the quick
> > processing of the patches, then the reworded commits have later time
> > stamps, but subsequent not reworded commits receive the earlier time
> > stamp. This is clearly not intended.
> 
> Oh dear, I think this is probably due to my series making rebase commit
> in-process when the commit message isn't being edited. I didn't realize
> that git cached the commit date rather than using the current time when
> calling commit_tree_extended(). I'll take a look at it next week.

Thanks.

However, a quick lock at `git log @{u}.. --format=%ct` in my `sequencer-shears` branch thicket (which I rebase frequently on top of upstream's `master` using the last known-good `rebase-merges` sub-branch) shows that the commits have different-enough commit timestamps. (It is satisfying to see that multiple commits were made during the same second, of course.)

So while I cannot find anything in the code that disagrees with Hannes' assessment, it looks on the surface as if I did not encounter the bug here.

Curious.

FWIW I agree with Hannes' patch.

> I think 'git am' probably gives all patches the same commit time as well
> if the commit date is cached though it wont suffer from the time-travel
> problem.

I thought that `git am` was the subject of such a complaint recently, but I thought that had been resolved? Apparently I misremember...

Ciao, Dscho