Re: history damage in linux.git

From: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
Date: Apr 21, 2016, 12:10 UTC
Message-ID: <vpqmvonw4a6.fsf@anie.imag.fr>
In-Reply-To: <20160421113004.GA3140@aepfle.de>

Olaf Hering <olaf@aepfle.de> writes:

Show 21 quoted lines

> To track the changes in hyperv related files I created some scripts
> years ago to automate the process of finding relevant commits in
> linux.git. Part of that process is to record the tag when a commit
> appeared in mainline. This worked fine, until very recently.
>
> Suddenly years-old commits are declared as having-just-arrived in
> linux.git. Look at this example:
>
>   $ git log --oneline -- drivers/input/serio/hyperv-keyboard.c
>   2048157 Drivers: hv: vmbus: fix the building warning with hyperv-keyboard
>   62238f3 Input: hyperv-keyboard - register as a wakeup source
>   c3c4d99 Input: hyperv-keyboard - pass through 0xE1 prefix
>   aed06b9 Input: add a driver to support Hyper-V synthetic keyboard
>   $ git describe --contains aed06b9
>   v4.6-rc1~9^2~792
>   $ git show aed06b9 | head
>   commit aed06b9cfcabf8644ac5f6f108c0b3d01522f88b
>   Author: K. Y. Srinivasan <kys@microsoft.com>
>   Date:   Wed Sep 18 12:50:42 2013 -0700
>
> Obviously that and other commits are in the tree since a very long time.

I cannot take that conclusion from the excerpts above. What I can conclude is that the commit was made a long time ago (according to https://github.com/torvalds/linux/commit/aed06b9cfcabf8644ac5f6f108c0b3d01522f88b the commit was initially made on Sep 18 2013 by K. Y. Srinivasan, and then applied by Dmitry Torokhov the day after to "some" tree.

My guess is that this commit has been sitting for a long time in a repo outside Linus' linux.git, and got merged only recently.

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/