[PATCHv2] Add --reference option to git submodule.

[PATCHv2] Add --reference option to git submodule.

[Michael S. Tsirkin]

This adds --reference option to git submodule add and
git submodule update commands, which is passed on to git clone.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

Here's v2. Ack?

Changes from v1: fixes in documentation, fix test usage and
make it portable.

 Documentation/git-submodule.txt |   14 ++++++++++++--
 git-submodule.sh                |   31 ++++++++++++++++++++++++++++---
 2 files changed, 40 insertions(+), 5 deletions(-)

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..4989d86 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" &&
@@ -321,6 +337,15 @@ cmd_update()
 			shift
 			nofetch=1
 			;;
+		--reference)
+			case "$2" in '') usage ;; esac
+			reference="$2"
+			shift 2
+			;;
+		--reference=*)
+			reference="$1"
+			shift
+			;;
 		--)
 			shift
 			break
@@ -351,7 +376,7 @@ 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" &&
-- 
1.6.3.rc3.dirty

Re: [PATCHv2] Add --reference option to git submodule.

[Michael J Gruber]

Michael S. Tsirkin venit, vidit, dixit 28.04.2009 14:30:
> This adds --reference option to git submodule add and
> git submodule update commands, which is passed on to git clone.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> 
> Here's v2. Ack?

I don't think it's up to me to Ack but you addressed my remarks.
BTW, even dash has "test STRING" so portability doesn't require -n but I
think it's OK either way.

Just be prepared in case someone asks for a test script ;)

Michael

> 
> Changes from v1: fixes in documentation, fix test usage and
> make it portable.
> 
>  Documentation/git-submodule.txt |   14 ++++++++++++--
>  git-submodule.sh                |   31 ++++++++++++++++++++++++++++---
>  2 files changed, 40 insertions(+), 5 deletions(-)
> 
> 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..4989d86 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" &&
> @@ -321,6 +337,15 @@ cmd_update()
>  			shift
>  			nofetch=1
>  			;;
> +		--reference)
> +			case "$2" in '') usage ;; esac
> +			reference="$2"
> +			shift 2
> +			;;
> +		--reference=*)
> +			reference="$1"
> +			shift
> +			;;
>  		--)
>  			shift
>  			break
> @@ -351,7 +376,7 @@ cmd_update()
>  
>  		if ! test -d "$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" &&

Re: [PATCHv2] Add --reference option to git submodule.

[Johannes Sixt]

Michael J Gruber schrieb:
> BTW, even dash has "test STRING" so portability doesn't require -n but I
> think it's OK either way.

It is not if STRING is user input; it could be, e.g., '-f', and then the
command gives a syntax error because of a missing argument.

It's safer to use test -z and test -n unless the string to test is
completely under the control of the script.

-- Hannes

Re: [PATCHv2] Add --reference option to git submodule.

[Michael J Gruber]

Johannes Sixt venit, vidit, dixit 28.04.2009 16:51:
> Michael J Gruber schrieb:
>> BTW, even dash has "test STRING" so portability doesn't require -n but I
>> think it's OK either way.
> 
> It is not if STRING is user input; it could be, e.g., '-f', and then the
> command gives a syntax error because of a missing argument.
> 
> It's safer to use test -z and test -n unless the string to test is
> completely under the control of the script.

Yep, that's true as a general rule. Here it's always preceeded by
"--reference=". But in any case I'm happy I suggested -n and it's in ;)

Michael

Re: [PATCHv2] Add --reference option to git submodule.

[Junio C Hamano]

Michael J Gruber <git@drmicha.warpmail.net> writes:

> Michael S. Tsirkin venit, vidit, dixit 28.04.2009 14:30:
>> This adds --reference option to git submodule add and
>> git submodule update commands, which is passed on to git clone.
>> 
>> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>> ---
>> 
>> Here's v2. Ack?
>
> I don't think it's up to me to Ack but you addressed my remarks.

You can certainly say "Reviewed-by: me" and/or "Tested-by: me".

> BTW, even dash has "test STRING" so portability doesn't require -n but I
> think it's OK either way.

It always is a good discipline and style.

Re: [PATCHv2] Add --reference option to git submodule.

[Michael S. Tsirkin]

On Tue, Apr 28, 2009 at 11:52:09AM -0700, Junio C Hamano wrote:
> Michael J Gruber <git@drmicha.warpmail.net> writes:
> 
> > Michael S. Tsirkin venit, vidit, dixit 28.04.2009 14:30:
> >> This adds --reference option to git submodule add and
> >> git submodule update commands, which is passed on to git clone.
> >> 
> >> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> >> ---
> >> 
> >> Here's v2. Ack?
> >
> > I don't think it's up to me to Ack but you addressed my remarks.
> 
> You can certainly say "Reviewed-by: me" and/or "Tested-by: me".

So ... Junio, what do you think about the patch?

-- 
MST