Re: Repeatable Extraction

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Oct 4, 2016, 10:25 UTC
Message-ID: <alpine.DEB.2.20.1610041223010.35196@virtualbox>
In-Reply-To: <CAJQwtsidixAAJKp7-b2PmXgs=mS+PbT5ebOmKLJU1nEn7UJ2og@mail.gmail.com>

Hi Chris,

On Tue, 27 Sep 2016, chris king wrote:

Show 8 quoted lines

> Is there a way automate extraction that will repeatably generate the
> same files? Currently, each time I extract git portable many of the
> binaries change slightly. For example, if I extract twice using
> 
>     PortableGit-2.10.0-32-bit.7z.exe -y -gm2
> 
> then Beyond Compare tells me that many of the files in usr\bin have
> changed at offset 0x88 and 0x89. Why is that?

The reason is that you look at 32-bit, where technical limitations force us to hard-code a certain base address for all of the includede MSYS2 .dll files (i.e. all libraries that require, or implement, the POSIX emulation layer called MSYS2).

To avoid clashes with other .dll files, that base address is adjusted via the post-install.bat script for your particular environment.

If you want to avoid that, you will have to extract the installer via 7-Zip: it is a self-extracting .7z archive (and the self-extractor automatically executes post-install.bat, which subsequently deletes itself).

Ciao, Johannes