Subject: Re: [RFC PATCH 3/3] filter-branch: support --submodule-filter

From: Jeffrey Phillips Freeman <[email-masked]>
Date: Mon, 03 Jan 2011 18:44:35 -0500

So im kinda new with all this so bare with me guys. I wanted to figure 
out how to apply these patches, now i know i can use git to do this with 
its patch command and such. However i was curious does this exist as a 
branch somewhere official or semi-official? I currently seem to be using 
--split-submodule which is itself in a git repo i have (which i want to 
also find its source repo so i can keep up to date with it). So applying 
the patch itself might be somewhat troubling due to conflicts, therefore 
id like to actually merge in a remote branch to keep things easy. So can 
you guys point me to which repo would be best for me to keep up to date 
with this would be?

On 12/31/2010 10:29 AM, Thomas Rast wrote:
> This new filter gets each submodule's current sha1 and path on stdin,
> separated by a tab.  It can then emit a new submodule sha1 and/or
> path, and filter-branch will:
>
> * if the path differs, remove the submodule at the old path;
>
> * add/replace the new sha1 at the new path.
>
> Additionally, returning an empty new sha1 deletes the submodule.
>
> You can tie this together with the last two commits to filter the
> super-project after a subproject filtering as follows:
>
>    ( cd sub1&&  git filter-branch --dump-map map<filters|args>  )
>    ( cd sub2&&  git filter-branch --dump-map map<filters|args>  )
>    cat sub1/map sub2/map>  map
>    git filter-branch --load-map map \
>    	--submodule-filter "map $(cut -f1)" \
> 	<args>
>
> Other use-cases should also be covered since we also pass through the
> path.
>
> Signed-off-by: Thomas Rast<[email-masked]>
> ---
>   git-filter-branch.sh |   24 ++++++++++++++++++++++++
>   1 files changed, 24 insertions(+), 0 deletions(-)
>
> diff --git a/git-filter-branch.sh b/git-filter-branch.sh
> index 9feeb26..4a321c4 100755
> --- a/git-filter-branch.sh
> +++ b/git-filter-branch.sh
> @@ -122,6 +122,7 @@ filter_msg=cat
>   filter_commit=
>   filter_tag_name=
>   filter_subdir=
> +filter_submodule=
>   orig_namespace=refs/original/
>   force=
>   prune_empty=
> @@ -193,6 +194,9 @@ do
>   		filter_subdir="$OPTARG"
>   		remap_to_ancestor=t
>   		;;
> +	--submodule-filter)
> +		filter_submodule="$OPTARG"
> +		;;
>   	--original)
>   		orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
>   		;;
> @@ -379,6 +383,26 @@ while read commit parents; do
>   	eval "$filter_index"<  /dev/null ||
>   		die "index filter failed: $filter_index"
>
> +	if [ "$filter_submodule" ]; then
> +		git ls-files -s |
> +		grep '^160000' |
> +		while read mode sha1 stage path; do
> +			printf "$sha1\t$path\n" |
> +			{ eval "$filter_submodule" ||
> +				die "submodule filter failed: $filter_submodule"; } |
> +			read newsha1 newpath
> +			if [ -z "$newsha1" ] || [ "$path" != "$newpath" ]; then
> +				git update-index --remove "$path" ||
> +					die "failed to remove submodule $path"
> +			fi
> +			if [ -n "$newsha1" ]&&  [ "$sha1" != "$newsha1" ]; then
> +				git update-index --add --replace --cacheinfo \
> +					160000 "$newsha1" "$newpath" ||
> +					die "failed to add submodule $newpath"
> +			fi
> +		done
> +	fi
> +
>   	parentstr=
>   	for parent in $parents; do
>   		for reparent in $(map "$parent"); do