Re: [RFC/PATCHv8 00/10] git notes

From: Junio C Hamano <gitster@pobox.com>
Date: Nov 20, 2009, 11:02 UTC
Message-ID: <7veintzcff.fsf@alter.siamese.dyndns.org>
In-Reply-To: <7vk4xl1nkl.fsf@alter.siamese.dyndns.org>

By the way, we could probably use this to make the command sequence even shorter.

I have to warn that this has never been used in real life, unlike the "checkout A...B" one --- caveat emptor.

Also I didn't bother touching up "rebase -i"; it is left as an excercise to the readers ;-)

-- >8 --
Subject: [PATCH] "rebase --onto A...B" replays history on the merge base between A and B

This is in spirit similar to "checkout A...B". To re-queue a new set of patches for a series that the original author prepared to apply on 'next' on the same base as before, you would do something like this:

    $ git checkout next^0
    $ git am -s rerolled-series.mbox
    $ git rebase --onto next...jh/notes next

The first two commands recreates commits to be rebased as the original author intended (i.e. applies directly on top of 'next'), and the rebase command replays that history on top of the same commit the series being replaced was built on (which is typically much older than the tip of 'next').

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-rebase.sh |   19 ++++++++++++++++++-
 1 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/git-rebase.sh b/git-rebase.sh
index 6830e16..570e2b6 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -34,6 +34,8 @@ set_reflog_action rebase
 require_work_tree
 cd_to_toplevel
 
+LF='
+'
 OK_TO_SKIP_PRE_REBASE=
 RESOLVEMSG="
 When you have resolved this problem run \"git rebase --continue\".
@@ -417,7 +419,22 @@ fi
 
 # Make sure the branch to rebase onto is valid.
 onto_name=${newbase-"$upstream_name"}
-onto=$(git rev-parse --verify "${onto_name}^0") || exit
+if	left=$(expr "$onto_name" : '\(.*\)\.\.\.') &&
+	right=$(expr "$onto_name" : '\.\.\.\(.*\)$') &&
+	: ${left:=HEAD} ${right:=HEAD} &&
+	onto=$(git merge-base "$left" "$right")
+then
+	case "$onto" in
+	?*"$LF"?*)
+		die "$onto_name: there are more than one merge bases"
+		;;
+	'')
+		die "$onto_name: there is no merge base"
+		;;
+	esac
+else
+	onto=$(git rev-parse --verify "${onto_name}^0") || exit
+fi
 
 # If a hook exists, give it a chance to interrupt
 run_pre_rebase_hook "$upstream_arg" "$@"

-- 
1.6.5.3.342.g14bb9