mergemaster feature suggestion...

[Robert Watson]

On Mon, 22 Dec 2003, Evren Yurtesen wrote:

> But also, does binary upgrade remove older files from /etc? I tried that
> only 1 time and it didnt even install half of the files required in /etc
> directory :) for example sshd conf files etc. were missing. Then I
> decided that I will not do that unless I absolutely need to.
> 
> I use build/install-world because I dont want to spend so much bandwidth
> and I prefer to get latest patches etc. easily. I want to have the
> possibility to go back to a date later on if I have a problem with the
> latest sources. So cvsup does that for me easily.
> 
> About those old files, I think any old file which doesnt exist in newer
> release does not only waste space and cause confusion. Also it might
> cause security problems. Considering, a problem in a file/binary
> whatever which does not exist in newer versions wouldnt be fixed by the
> freebsd developers. However it is a small possibility.
> 
> I often thought of a way to remove older files. I even considered making
> a fresh install of the latest version of FreeBSD to a test machine and
> compare the file structures to remove files from the actual machines. 
> But there can be an utility to do that right? If there is an utility to
> compare the files and install (mergemaster) there can be an utility to
> remove the older files also, or this can be implemented inside
> mergemaster as an option/

You might want to take a look at Eivind's "etcmerge" port in
ports/sysutils/etcmerge.  mergemaster does a two-way merge between
"old+modified" and "new" and so can't tell the difference between old
versions and your modifications, so has to err on the safe side except
when specifically told about removing things (such as clearing out some
specific stuff from earlier rcNG, and pre-rcNG stuff).  etcmerge tracks
three version: "old", "old+modifications", and "new", so it can identify
your modifications and preserve them better, as well as tell if files have
been removed.  I'm not using it myself currently, but have been thinking
of starting to use it ever since Eivind pointed it out to me.  Maybe give
it a spin and tell me how it works out :-). 

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert at fledge.watson.org      Senior Research Scientist, McAfee Research