Re: [PATCHv3] Add --reference option to git submodule.

[Michael J Gruber <git@drmicha.warpmail.net>]

Michael S. Tsirkin venit, vidit, dixit 04.05.2009 21:30:
> This adds --reference option to git submodule add and
> git submodule update commands, which is passed to git clone.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> 
> I think it's ready now :) Comments?

Please don't expect Junio to look at this now, shortly before 1.6.3. I
think only regression fixes would go in now, not even other bug fixes.
Holding on to your patch and re-posting after the upcoming release of
1.6.3 should be your best option.

Cheers,
Michael

> 
> Changes from v2: added test script, fixed update --reference with --init.
> 
> Changes from v1: fixes in documentation, fix test usage and
> make it portable.
> 
>  Documentation/git-submodule.txt |   14 ++++++-
>  git-submodule.sh                |   38 ++++++++++++++++--
>  t/t7406-submodule-reference.sh  |   81 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 127 insertions(+), 6 deletions(-)
>  create mode 100755 t/t7406-submodule-reference.sh
> 
> diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
> index 3b8df44..14256c6 100644
> --- a/Documentation/git-submodule.txt
> +++ b/Documentation/git-submodule.txt
> @@ -9,10 +9,12 @@ git-submodule - Initialize, update or inspect submodules
>  SYNOPSIS
>  --------
>  [verse]
> -'git submodule' [--quiet] add [-b branch] [--] <repository> <path>
> +'git submodule' [--quiet] add [-b branch]
> +	      [--reference <repository>] [--] <repository> <path>
>  'git submodule' [--quiet] status [--cached] [--] [<path>...]
>  'git submodule' [--quiet] init [--] [<path>...]
> -'git submodule' [--quiet] update [--init] [-N|--no-fetch] [--] [<path>...]
> +'git submodule' [--quiet] update [--init] [-N|--no-fetch]
> +	      [--reference <repository>] [--] [<path>...]
>  'git submodule' [--quiet] summary [--summary-limit <n>] [commit] [--] [<path>...]
>  'git submodule' [--quiet] foreach <command>
>  'git submodule' [--quiet] sync [--] [<path>...]
> @@ -177,6 +179,14 @@ OPTIONS
>  	This option is only valid for the update command.
>  	Don't fetch new objects from the remote site.
>  
> +--reference <repository>::
> +	This option is only valid for add and update commands.  These
> +	commands sometimes need to clone a remote repository. In this case,
> +	this option will be passed to the linkgit:git-clone[1] command.
> ++
> +*NOTE*: Do *not* use this option unless you have read the note
> +for linkgit:git-clone[1]'s --reference and --shared options carefully.
> +
>  <path>...::
>  	Paths to submodule(s). When specified this will restrict the command
>  	to only operate on the submodules found at the specified paths.
> diff --git a/git-submodule.sh b/git-submodule.sh
> index 8e234a4..ab1ed02 100755
> --- a/git-submodule.sh
> +++ b/git-submodule.sh
> @@ -15,6 +15,7 @@ require_work_tree
>  command=
>  branch=
>  quiet=
> +reference=
>  cached=
>  nofetch=
>  
> @@ -91,6 +92,7 @@ module_clone()
>  {
>  	path=$1
>  	url=$2
> +	reference="$3"
>  
>  	# If there already is a directory at the submodule path,
>  	# expect it to be empty (since that is the default checkout
> @@ -106,7 +108,12 @@ module_clone()
>  	test -e "$path" &&
>  	die "A file already exist at path '$path'"
>  
> -	git-clone -n "$url" "$path" ||
> +	if test -n "$reference"
> +	then
> +		git-clone "$reference" -n "$url" "$path"
> +	else
> +		git-clone -n "$url" "$path"
> +	fi ||
>  	die "Clone of '$url' into submodule path '$path' failed"
>  }
>  
> @@ -131,6 +138,15 @@ cmd_add()
>  		-q|--quiet)
>  			quiet=1
>  			;;
> +		--reference)
> +			case "$2" in '') usage ;; esac
> +			reference="--reference=$2"
> +			shift
> +			;;
> +		--reference=*)
> +			reference="$1"
> +			shift
> +			;;
>  		--)
>  			shift
>  			break
> @@ -203,7 +219,7 @@ cmd_add()
>  		git config submodule."$path".url "$url"
>  	else
>  
> -		module_clone "$path" "$realrepo" || exit
> +		module_clone "$path" "$realrepo" "$reference" || exit
>  		(
>  			unset GIT_DIR
>  			cd "$path" &&
> @@ -314,13 +330,22 @@ cmd_update()
>  			quiet=1
>  			;;
>  		-i|--init)
> +			init=1
>  			shift
> -			cmd_init "$@" || return
>  			;;
>  		-N|--no-fetch)
>  			shift
>  			nofetch=1
>  			;;
> +		--reference)
> +			case "$2" in '') usage ;; esac
> +			reference="--reference=$2"
> +			shift 2
> +			;;
> +		--reference=*)
> +			reference="$1"
> +			shift
> +			;;
>  		--)
>  			shift
>  			break
> @@ -334,6 +359,11 @@ cmd_update()
>  		esac
>  	done
>  
> +	if test -n "$init"
> +	then
> +		cmd_init "--" "$@" || return
> +	fi
> +
>  	module_list "$@" |
>  	while read mode sha1 stage path
>  	do
> @@ -351,7 +381,7 @@ cmd_update()
>  
>  		if ! test -d "$path"/.git -o -f "$path"/.git
>  		then
> -			module_clone "$path" "$url" || exit
> +			module_clone "$path" "$url" "$reference"|| exit
>  			subsha1=
>  		else
>  			subsha1=$(unset GIT_DIR; cd "$path" &&
> diff --git a/t/t7406-submodule-reference.sh b/t/t7406-submodule-reference.sh
> new file mode 100755
> index 0000000..cc16d3f
> --- /dev/null
> +++ b/t/t7406-submodule-reference.sh
> @@ -0,0 +1,81 @@
> +#!/bin/sh
> +#
> +# Copyright (c) 2009, Red Hat Inc, Author: Michael S. Tsirkin (mst@redhat.com)
> +#
> +
> +test_description='test clone --reference'
> +. ./test-lib.sh
> +
> +base_dir=`pwd`
> +
> +U=$base_dir/UPLOAD_LOG
> +
> +test_expect_success 'preparing first repository' \
> +'test_create_repo A && cd A &&
> +echo first > file1 &&
> +git add file1 &&
> +git commit -m A-initial'
> +
> +cd "$base_dir"
> +
> +test_expect_success 'preparing second repository' \
> +'git clone A B && cd B &&
> +echo second > file2 &&
> +git add file2 &&
> +git commit -m B-addition &&
> +git repack -a -d &&
> +git prune'
> +
> +cd "$base_dir"
> +
> +test_expect_success 'preparing supermodule' \
> +'test_create_repo super && cd super &&
> +echo file > file &&
> +git add file &&
> +git commit -m B-super-initial'
> +
> +cd "$base_dir"
> +
> +test_expect_success 'submodule add --reference' \
> +'cd super && git submodule add --reference ../B "file://$base_dir/A" sub &&
> +git commit -m B-super-added'
> +
> +cd "$base_dir"
> +
> +test_expect_success 'after add: existence of info/alternates' \
> +'test `wc -l <super/sub/.git/objects/info/alternates` = 1'
> +
> +cd "$base_dir"
> +
> +test_expect_success 'that reference gets used with add' \
> +'cd super/sub &&
> +echo "0 objects, 0 kilobytes" > expected &&
> +git count-objects > current &&
> +diff expected current'
> +
> +cd "$base_dir"
> +
> +test_expect_success 'cloning supermodule' \
> +'git clone super super-clone'
> +
> +cd "$base_dir"
> +
> +test_expect_success 'update with reference' \
> +'cd super-clone && git submodule update --init --reference ../B'
> +
> +cd "$base_dir"
> +
> +test_expect_success 'after update: existence of info/alternates' \
> +'test `wc -l <super-clone/sub/.git/objects/info/alternates` = 1'
> +
> +cd "$base_dir"
> +
> +test_expect_success 'that reference gets used with update' \
> +'cd super-clone/sub &&
> +echo "0 objects, 0 kilobytes" > expected &&
> +git count-objects > current &&
> +diff expected current'
> +
> +cd "$base_dir"
> +
> +test_done