Re: [PATCH 04/10] checkout --conflict=diff3: add a label for ancestor

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 15, 2010, 08:20 UTC
Message-ID: <7vvdcy0zf3.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20100315075509.GD8824@progeny.tock>

Jonathan Nieder <jrnieder@gmail.com> writes:

Show 24 quoted lines

> git checkout --conflict=diff3 can be used to present conflicts hunks
> including text from the common ancestor:
>
> 	<<<<<<< ours
> 	ourside
> 	|||||||
> 	original
> 	=======
> 	theirside
> 	>>>>>>> theirs
>
> The added information can be very helpful for resolving a merge by
> hand, and merge tools can usually understand it without trouble
> because it looks like output from ‘diff3 -m’.
>
> Unfortunately, not all can: ‘diff3’ includes a label for the merge
> base on the ||||||| line and it seems some tools cannot parse conflict
> hunks without such a label.  Humans could use help in interpreting the
> output, too.  So mark the start of the text from the common ancestor
> with the label “||||||| original”.
>
> git rerere will not have trouble parsing this output, since instead of
> looking for a newline, it looks for whitespace after the |||||||
> marker.

Missing:

    "... and adding the extra label will not affect the computed the conflict
    identifier, so existing rerere database will not be invalidated with this
    change either".

I didn't verified the above claim, but if it does not hold true, then we need to think the transition strategy. I don't expect a problem, though.

> Reported-by: Stefan Monnier <monnier@iro.umontreal.ca>
> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

This "Reported" feels very odd for a feature enhancement ("Requested" would be more appropriate) not a bugfix.

> ---
> Since “original” a good name for the common ancestor?  I also
> considered “base” and “ancestor”; the latter is too jargon-y for my
> taste, but “base” seems all right.

Yeah, base sounds good. Even though at the lowest level, a merge is a merge between two equals, people tend to think of the contents of their own side "original" (vs the merge outcome "result").