Re: [PATCH] Fix rebase -p --onto
- From
Greg Price <price@ksplice.com>
- Date
- Jul 17, 2009, 16:33 UTC
- Message-ID
- <20090717163350.GK7878@vinegar-pot.mit.edu>
- In-Reply-To
- <7vk52767el.fsf@alter.siamese.dyndns.org>
On Fri, Jul 17, 2009 at 01:27:46AM -0700, Junio C Hamano wrote:
Show 18 quoted lines
> Hmm, if the original history were > > .---X---o---o---o---M > \ / > x---x---x---x---x > > Y > > and the rebase is about moving history leading to M since X on top of Y, > I would actually have agreed that this > > .---X---o---o---o---M > \ / > x---x---x---x---x > \ > Y---o'--o'--o'--M' > > would be the right thing to do (IOW, I would agree with you).
Yes, I agree.
> Can the current code distinguish the two cases?
Yes. Stephen's commit acc8559 already limits $TODO to the descendants of the merge-bases of HEAD and UPSTREAM, which captures the distinction here. When we rebase from X, the merge-base is X, so only that branch moves. When we rebase from the base of both branches, both branches should move.
I've added a test demonstrating this case to a revised version of the patch, below.
Greg
>From dcab1103e14394364c15136823269416f8c56e97 Mon Sep 17 00:00:00 2001
From: Greg Price <price@ksplice.com> Date: Thu, 16 Jul 2009 12:48:40 -0400 Subject: [PATCH] Fix rebase -p --onto
In a rebase with --onto, the correct test for whether we can skip rewriting a commit is if it is already on top of $ONTO, not $UPSTREAM. Without --onto, this distinction does not exist and the behavior does not change.
In the situation
X---o---o---o---M \ / x---x---x---x
Y
if we try to move the branches merged at M from their base on X to be based on Y, so as to get
X
Y---o'--o'--o'--M' \ / x'--x'--x'--x'
then we fail. The command `git rebase -p --onto Y X M` moves only the first-parent chain, like so:
X
\
x---x---x---x
\
Y---o'--o'--o'--M'because it mistakenly drops the other branch(es) x---x---x---x from the TODO file. This tests and fixes this behavior.
Signed-off-by: Greg Price <price@ksplice.com> --- git-rebase--interactive.sh | 2 +- t/t3414-rebase-preserve-onto.sh | 80 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 81 insertions(+), 1 deletions(-) create mode 100755 t/t3414-rebase-preserve-onto.sh
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh index f96d887..23ded48 100755 --- a/git-rebase--interactive.sh +++ b/git-rebase--interactive.sh @@ -703,7 +703,7 @@ first and then run 'git rebase --continue' again." preserve=t for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -s -f2-) do - if test -f "$REWRITTEN"/$p -a \( $p != $UPSTREAM -o $sha1 = $first_after_upstream \) + if test -f "$REWRITTEN"/$p -a \( $p != $ONTO -o $sha1 = $first_after_upstream \) then preserve=f fi diff --git a/t/t3414-rebase-preserve-onto.sh b/t/t3414-rebase-preserve-onto.sh new file mode 100755 index 0000000..80019ee --- /dev/null +++ b/t/t3414-rebase-preserve-onto.sh @@ -0,0 +1,80 @@ +#!/bin/sh +# +# Copyright (c) 2009 Greg Price +# + +test_description='git rebase -p should respect --onto + +In a rebase with --onto, we should rewrite all the commits that +aren'"'"'t on top of $ONTO, even if they are on top of $UPSTREAM. +' +. ./test-lib.sh + +. ../lib-rebase.sh + +# Set up branches like this: +# A1---B1---E1---F1---G1 +# \ \ / +# \ \--C1---D1--/ +# H1 + +test_expect_success 'setup' ' + test_commit A1 && + test_commit B1 && + test_commit C1 && + test_commit D1 && + git reset --hard B1 && + test_commit E1 && + test_commit F1 && + test_merge G1 D1 && + git reset --hard A1 && + test_commit H1 +' + +# Now rebase merge G1 from both branches' base B1, both should move: +# A1---B1---E1---F1---G1 +# \ \ / +# \ \--C1---D1--/ +# \ +# H1---E2---F2---G2 +# \ / +# \--C2---D2--/ + +test_expect_success 'rebase from B1 onto H1' ' + git checkout G1 && + git rebase -p --onto H1 B1 && + test "$(git rev-parse HEAD^1^1^1)" = "$(git rev-parse H1)" && + test "$(git rev-parse HEAD^2^1^1)" = "$(git rev-parse H1)" +' + +# On the other hand if rebase from E1 which is within one branch, +# then the other branch stays: +# A1---B1---E1---F1---G1 +# \ \ / +# \ \--C1---D1--/ +# \ \ +# H1-----F3-----G3 + +test_expect_success 'rebase from E1 onto H1' ' + git checkout G1 && + git rebase -p --onto H1 E1 && + test "$(git rev-parse HEAD^1^1)" = "$(git rev-parse H1)" && + test "$(git rev-parse HEAD^2)" = "$(git rev-parse D1)" +' + +# And the same if we rebase from a commit in the second-parent branch. +# A1---B1---E1---F1----G1 +# \ \ \ / +# \ \--C1---D1-\-/ +# \ \ +# H1------D3------G4 + +test_expect_success 'rebase from C1 onto H1' ' + git checkout G1 && + git rev-list --first-parent --pretty=oneline C1..G1 && + git rebase -p --onto H1 C1 && + test "$(git rev-parse HEAD^2^1)" = "$(git rev-parse H1)" && + test "$(git rev-parse HEAD^1)" = "$(git rev-parse F1)" +' + +test_done
-- 1.6.3.1.499.ge7b8da