Re: [PATCH] rebase with preserve merges should not show merged commits

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Mar 22, 2008, 01:33 UTC
Message-ID: <alpine.LSU.1.00.0803220231020.4124@racer.site>
In-Reply-To: <1206148785-29466-1-git-send-email-joerg@alea.gnuu.de>

Hi,

On Sat, 22 Mar 2008, Jörg Sommer wrote:

Show 11 quoted lines

> The current version of git-rebase--interactive shows the user the 
> commits coming from a merge.
> 
> M---A---B
>  \       \
>   o---o---+---o branch
> 
> Rebasing branch on M with preserve merges gives the commits A and B. But 
> if you mark them for editing or remove them the rebase fails. You must 
> keep them as they are. It's useless to bother the user with these 
> commits and might lead to mistakes.

I don't understand. Rebasing with "rebase --onto <something else> M" _should_ show A and B.

Besides, I think that this would break exactly that case:

Show 6 quoted lines

> @@ -523,7 +525,7 @@ do
>  		SHORTONTO=$(git rev-parse --short $ONTO)
>  		git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
>  			--abbrev=7 --reverse --left-right --cherry-pick \
> -			$UPSTREAM...$HEAD | \
> +			--first-parent $UPSTREAM...$HEAD | \

If I am not mistaken, you now mark A and B to be _not_ in the list of commits all of a sudden, even if A and B _are_ reachable from "branch", but not from "M".

So I think this is exactly one of the cases which made me unsure if your expectation was always right.

IOW I think this is _very_ easy to get wrong, and needs careful thought.

Ciao, Dscho