[PATCH] Make rebase save ORIG_HEAD if using current branch

This makes rebase act a little more like merge when working on the
current branch.  This is particularly useful for `git pull --rebase`

Signed-off-by: Brian Gernhardt <redacted>
---

 I was trying to figure out why reviewing the new changes in git was so
 hard using my `git log ORIG_HEAD..` alias.  Turns out my ORIG_HEAD
 hadn't been updated since Feburary, which is when I set
 branch.master.rebase to true.

 I think ORIG_HEAD should be set every time a pull changes HEAD, whether
 by a merge or rebase.  Making rebase act like merge seemed more elegant
 than having git-pull set ORIG_HEAD iff using rebase.

 git-rebase.sh |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/git-rebase.sh b/git-rebase.sh
index 9b13b83..8d54d9f 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh

@@ -342,6 +342,7 @@ case "$#" in
 		branch_name=HEAD ;# detached
 	fi
 	branch=$(git rev-parse --verify "${branch_name}^0") || exit
+	echo "$branch" > "$GIT_DIR/ORIG_HEAD"
 	;;
 esac
 orig_head=$branch

-- 
1.5.5.1.242.g558e8

Brian Gernhardt schrieb:

1. You should be using 'git update-ref' here, I think.
2. You should detect errors.
3. Should ORIG_HEAD better be set at the end of the rebase, not at the
beginning? Because if the rebase stops for some reason, and then you do a
'git reset', you'll have overwritten the ORIG_HEAD that you have set here.

-- Hannes

On May 6, 2008, at 2:32 AM, Johannes Sixt wrote:

Brian Gernhardt schrieb:

quoted

diff --git a/git-rebase.sh b/git-rebase.sh
index 9b13b83..8d54d9f 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh

@@ -342,6 +342,7 @@ case "$#" in

		branch_name=HEAD ;# detached
	fi
	branch=$(git rev-parse --verify "${branch_name}^0") || exit
+	echo "$branch" > "$GIT_DIR/ORIG_HEAD"

1. You should be using 'git update-ref' here, I think.
2. You should detect errors.

This is exactly how git-merge.sh does it.  While that's not a good  
argument for adding this, perhaps merge should be updated as well.   
And presumably update-ref will make detecting errors easy.  But is  
being unable to set ORIG_HEAD an error that should stop the entire  
process?

3. Should ORIG_HEAD better be set at the end of the rebase, not at the
beginning? Because if the rebase stops for some reason, and then you  
do a
'git reset', you'll have overwritten the ORIG_HEAD that you have set  
here.

I put it where I did because I thought it would only make sense when  
rebasing the current HEAD (instead of the two argument version that  
switches first).  Duplicating the logic to determine that later seemed  
wasteful.  Also, might you want to access the original HEAD during a  
rebase conflict?  (Although that would argue that ORIG_HEAD should be  
set for all rebases, to $upstream.)

~~ Brian

Brian Gernhardt schrieb:

On May 6, 2008, at 2:32 AM, Johannes Sixt wrote:

quoted

Brian Gernhardt schrieb:

quoted

+    echo "$branch" > "$GIT_DIR/ORIG_HEAD"

1. You should be using 'git update-ref' here, I think.
2. You should detect errors.

This is exactly how git-merge.sh does it.  While that's not a good
argument for adding this, perhaps merge should be updated as well.  And
presumably update-ref will make detecting errors easy.  But is being
unable to set ORIG_HEAD an error that should stop the entire process?

Probably not.

quoted

3. Should ORIG_HEAD better be set at the end of the rebase, not at the
beginning? Because if the rebase stops for some reason, and then you do a
'git reset', you'll have overwritten the ORIG_HEAD that you have set
here.

I put it where I did because I thought it would only make sense when
rebasing the current HEAD (instead of the two argument version that
switches first).  Duplicating the logic to determine that later seemed
wasteful.  Also, might you want to access the original HEAD during a
rebase conflict?  (Although that would argue that ORIG_HEAD should be
set for all rebases, to $upstream.)

Well, I can't think of a use-case where ORIG_HEAD would be extremly useful
for _me_, but you argued for one (git pull --rebase), so you make it so
that it suits you. I'm just drawing a scenario where ORIG_HEAD possibly is
not what you expect.

-- Hannes