Add --ignore-missing to git-pack-objects?

Add --ignore-missing to git-pack-objects?

[ch]

Hi.

Is it possible to add an option akin to git-rev-list's '--ignore-missing' to
git-pack-objects?

I use git bundles to (incrementally) backup my repositories. My script inspects
all bundles in the backup and passes their contained refs as excludes to
git-pack-objects to build the pack for the new bundle. This works fine as long
as none of these refs have been garbage-collected in the source repository.
Something like '--ignore-missing' would be really handy here to ask
git-pack-objects to simply ignore any of the passed revs that are not present
(anymore).

Thanks in advance.

Re: Add --ignore-missing to git-pack-objects?

[Jeff King]

On Tue, Aug 15, 2017 at 12:51:01AM +0200, ch wrote:

> Is it possible to add an option akin to git-rev-list's '--ignore-missing' to
> git-pack-objects?
> 
> I use git bundles to (incrementally) backup my repositories. My script inspects
> all bundles in the backup and passes their contained refs as excludes to
> git-pack-objects to build the pack for the new bundle. This works fine as long
> as none of these refs have been garbage-collected in the source repository.
> Something like '--ignore-missing' would be really handy here to ask
> git-pack-objects to simply ignore any of the passed revs that are not present
> (anymore).

So if I understand correctly, you are only using these for the negative
side of the traversal? rev-list should ignore missing objects in such a
case even without --ignore-missing, and I think it may simply be a bug
if pack-objects is not.

Do you have a simple reproduction recipe?

-Peff

Re: Add --ignore-missing to git-pack-objects?

[ch]

Hi Jeff.

Thanks a lot for your response.

Jeff King wrote:

> So if I understand correctly, you are only using these for the negative
> side of the traversal?

Yes.

Jeff King wrote:

> rev-list should ignore missing objects in such a
> case even without --ignore-missing, and I think it may simply be a bug
> if pack-objects is not.
> 
> Do you have a simple reproduction recipe?

Here's a small bash script to illustrate the core issue:

----
add_file()
{
     echo "$1" > "$1"
     git add "$1"
     git commit -m "$1"
}

git init .
git config core.logAllRefUpdates false

add_file "test-1"
add_file "test-2"

git checkout -b feature

add_file "test-3"
add_file "test-4"

git checkout master

add_file "test-5"
add_file "test-6"

feature_tip=$(git rev-list -1 feature)

echo -e "\nDeleting branch 'feature' ($feature_tip)..."
git branch -D feature
git gc --prune=now

echo -e "\nCalling git-pack-objects with (now deleted) ^$feature_tip..."
git pack-objects --all --revs --stdout --thin --delta-base-offset --all-progress-implied <<< ^$feature_tip > pack

echo -e "\nCalling git-rev-list with (now deleted) ^$feature_tip..."
git rev-list --all ^$feature_tip

echo -e "\nCalling git-rev-list --ignore-missing with (now deleted) ^$feature_tip..."
git rev-list --all --ignore-missing ^$feature_tip
----

Both, git-pack-objects and git-rev-list (without --ignore-missing) fail with

fatal: bad object <feature_tip>

on git version 2.14.1.windows.1.