Re: [PATCH 0/3] merge -Xindex-only

[Michael Haggerty <mhagger@alum.mit.edu>]

On 07/09/2013 02:08 PM, Thomas Rast wrote:
> Michael Haggerty <mhagger@alum.mit.edu> writes:
> 
>> Since you've already implemented a way to merge into the index (even an
>> alternative index) without touching the working copy, I'll just cross my
>> fingers and hope for the appearance of an option that makes merge leave
>> HEAD, MERGE_HEAD, etc. untouched.
> 
> The most annoying part is probably where to put the output, since
> merging is more or less defined to do one of:
> 
> - update HEAD and return 0
> - update MERGE_HEAD and return 1

I don't understand what you mean here.  Why does *any* reference need to
be updated?  Why not

* load arbitrary commit-ish A into index

* merge arbitrary commit-ish B into index

* return error/OK depending on whether there was a conflict

?  The script that started the whole process would know what A and B are
and could create the commit itself using "git write-tree" and "git
commit-tree -p A -p B".  And if the index were an alternative index
chosen via GIT_INDEX_FILE then the rest of the git repo would be none
the wiser.

> I'm not sure how much flexibility is worth having.  Would it be
> sufficient if you had an option, e.g. -Xresult-ref=refs/heads/foo, that
> changes it to:
> 
> - update refs/heads/foo and return 0
> - return 1, not updating any refs
> 
> That would mean that it would only work for noninteractive use.  In the
> conflicting case, the driving script would need to remember what it
> wanted to merge so as have the information when finally committing.

That would be fine with me.

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu
http://softwareswirl.blogspot.com/