threads / patch / 12474

patchgit-submodule - Allow adding a submodule in-place

Subject: [PATCH] git-submodule - Allow adding a submodule in-place

## tl;dr

6 messages between Mar 4, 2008 and Mar 5, 2008. Diffs are folded; open one to read it.

replies: 5people: 4as markdown or json

Mark Levedahl· Mar 4, 2008, 02:06 UTC · lore

When working in top-level project, it is useful to create a new submodule as a git repo in a subdirectory, then add that submodule to top-level in place. This allows "git submodule add <intended url> subdir" to add the existing subdir to the current project. The presumption is the user will later push / clone the subdir to the <intended url> so that future submodule init / updates will work.

Absent this patch, "git submodule add" insists upon cloning the subdir from a repository at the given url, which is fine for adding an existing project in but less useful when adding a new submodule from scratch to an existing project. The former functionality remains, and the clone is attempted if the subdir does not already exist as a valid git repo.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>
---
 Documentation/git-submodule.txt |   21 +++++++++++++---
 git-submodule.sh                |   50 +++++++++++++++++++++++---------------
 2 files changed, 47 insertions(+), 24 deletions(-)
Show changes to 2 files +47 −24

Documentation/git-submodule.txt, git-submodule.sh

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index e818e6e..85d7dd3 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -9,17 +9,18 @@ git-submodule - Initialize, update or inspect submodules
 SYNOPSIS
 --------
 [verse]
-'git-submodule' [--quiet] add [-b branch] [--] <repository> [<path>]
+'git-submodule' [--quiet] add [-b branch] [-r <remote>] [--] <repository> [<path>]
 'git-submodule' [--quiet] status [--cached] [--] [<path>...]
-'git-submodule' [--quiet] [init|update] [--] [<path>...]
+'git-submodule' [--quiet] [init|update] [-r <remote>] [--] [<path>...]
 
 
 COMMANDS
 --------
 add::
 	Add the given repository as a submodule at the given path
-	to the changeset to be committed next.  In particular, the
-	repository is cloned at the specified path, added to the
+	to the changeset to be committed next.  If path is a valid
+	repository within the project, it is added as is. Otherwise,
+	repository is cloned at the specified path. path is added to the
 	changeset and registered in .gitmodules.   If no path is
 	specified, the path is deduced from the repository specification.
 	If the repository url begins with ./ or ../, it is stored as
@@ -55,6 +56,18 @@ OPTIONS
 -b, --branch::
 	Branch of repository to add as submodule.
 
+-r remote::
+	Name of remote to use or define when working with relative submodules
+	(i.e., submodules whose url is given relative to the top-level
+	project). If this value is undefined, the top-level project's
+	branch.<name>.remote is used, and if that is undefined the default
+	"origin" is used. The remote will be defined in each relative
+	submodule as needed by appending the relative url to the top level
+	project's url. This option has no effect upon submodules defined
+	using an absolute url: such project's are cloned using the default
+	"origin," and are updated using the submodule's branch.<name>.remote
+	machinery and defaulting to "origin."
+
 --cached::
 	Display the SHA-1 stored in the index, not the SHA-1 of the currently
 	checked out submodule commit. This option is only valid for the
diff --git a/git-submodule.sh b/git-submodule.sh
index 67d3224..7171cb6 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -153,20 +153,6 @@ cmd_add()
 		usage
 	fi
 
-	case "$repo" in
-	./*|../*)
-		# dereference source url relative to parent's url
-		realrepo="$(resolve_relative_url $repo)" ;;
-	*)
-		# Turn the source into an absolute path if
-		# it is local
-		if base=$(get_repo_base "$repo"); then
-			repo="$base"
-		fi
-		realrepo=$repo
-		;;
-	esac
-
 	# Guess path from repo if not specified or strip trailing slashes
 	if test -z "$path"; then
 		path=$(echo "$repo" | sed -e 's|/*$||' -e 's|:*/*\.git$||' -e 's|.*[/:]||g')
@@ -174,15 +160,39 @@ cmd_add()
 		path=$(echo "$path" | sed -e 's|/*$||')
 	fi
 
-	test -e "$path" &&
-	die "'$path' already exists"
-
 	git ls-files --error-unmatch "$path" > /dev/null 2>&1 &&
 	die "'$path' already exists in the index"
 
-	module_clone "$path" "$realrepo" || exit
-	(unset GIT_DIR; cd "$path" && git checkout -q ${branch:+-b "$branch" "origin/$branch"}) ||
-	die "Unable to checkout submodule '$path'"
+	# perhaps the path exists and is already a git repo, else clone it
+	if test -e "$path"
+	then
+		if test -d "$path/.git" &&
+		test "$(unset GIT_DIR; cd $path; git rev-parse --git-dir)" = ".git"
+		then
+			echo "Adding existing repo at '$path' to the index"
+		else
+			die "'$path' already exists and is not a valid git repo"
+		fi
+	else
+		case "$repo" in
+		./*|../*)
+			# dereference source url relative to parent's url
+			realrepo="$(resolve_relative_url $repo)" ;;
+		*)
+			# Turn the source into an absolute path if
+			# it is local
+			if base=$(get_repo_base "$repo"); then
+				repo="$base"
+			fi
+			realrepo=$repo
+			;;
+		esac
+
+		module_clone "$path" "$realrepo" || exit
+		(unset GIT_DIR; cd "$path" && git checkout -q ${branch:+-b "$branch" "origin/$branch"}) ||
+		die "Unable to checkout submodule '$path'"
+	fi
+
 	git add "$path" ||
 	die "Failed to add submodule '$path'"
 
-- 
1.5.4.3.438.g4c6f8
Ping Yin· Mar 4, 2008, 05:16 UTC · re: Mark Levedahl · lore

Re: [PATCH] git-submodule - Allow adding a submodule in-place

On Tue, Mar 4, 2008 at 10:06 AM, Mark Levedahl <mlevedahl@gmail.com> wrote:
Show 13 quoted lines
>
>  +-r remote::
>  +       Name of remote to use or define when working with relative submodules
>  +       (i.e., submodules whose url is given relative to the top-level
>  +       project). If this value is undefined, the top-level project's
>  +       branch.<name>.remote is used, and if that is undefined the default
>  +       "origin" is used. The remote will be defined in each relative
>  +       submodule as needed by appending the relative url to the top level
>  +       project's url. This option has no effect upon submodules defined
>  +       using an absolute url: such project's are cloned using the default
>  +       "origin," and are updated using the submodule's branch.<name>.remote
>  +       machinery and defaulting to "origin."
>  +
Is this part necessary?
>  --
>  1.5.4.3.438.g4c6f8
>
>
-- 
Ping Yin
Junio C Hamano· Mar 4, 2008, 07:09 UTC · re: Mark Levedahl · lore

Re: [PATCH] git-submodule - Allow adding a submodule in-place

Mark Levedahl <mlevedahl@gmail.com> writes:
Show 14 quoted lines
> When working in top-level project, it is useful to create a new submodule
> as a git repo in a subdirectory, then add that submodule to top-level in
> place.  This allows "git submodule add <intended url> subdir" to add the
> existing subdir to the current project.  The presumption is the user will
> later push / clone the subdir to the <intended url> so that future
> submodule init / updates will work.
>
> Absent this patch, "git submodule add" insists upon cloning the subdir
> from a repository at the given url, which is fine for adding an existing
> project in but less useful when adding a new submodule from scratch to an
> existing project.  The former functionality remains, and the clone is
> attempted if the subdir does not already exist as a valid git repo.
>
> Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>

This is a very well written commit log message with an appropriate title, and a convincing justification why this is a good idea. Even I (who does not heavily use submodules himself) can look at the patch and tell that the existing check and die was too limiting to the users after reading these two paragraphs.

I wish everybody wrote his commit log message like this.
Show 12 quoted lines
> +-r remote::
> +	Name of remote to use or define when working with relative submodules
> +	(i.e., submodules whose url is given relative to the top-level
> +	project). If this value is undefined, the top-level project's
> +	branch.<name>.remote is used, and if that is undefined the default
> +	"origin" is used. The remote will be defined in each relative
> +	submodule as needed by appending the relative url to the top level
> +	project's url. This option has no effect upon submodules defined
> +	using an absolute url: such project's are cloned using the default
> +	"origin," and are updated using the submodule's branch.<name>.remote
> +	machinery and defaulting to "origin."
> +
However, this part is not mentioned in the commit log message at all.
Is the enhancement advertised on the title line be useful _without_ this?

If so, this is a commit with two unrelated changes, and needs to be split into two patches. Also the other change that adds "-r remote" needs to be explained and defended separately.

If not, the additional option should be described (what it does) justified (why it is needed), and also there needs an explanation why this is an integral part of the addition of this "add existing subdirectory" feature.

Yes, I _can_ guess that this option is related to your earlier f31a522 (git-submodule - allow a relative path as the subproject url). Because "submodule add" is used for setting up the initial .gitmodules entry for the new submodule, you would need to give a clue to the command if you want to set it up as a relative thing or an absolute thing, and you use the relativeness of the URL parameter for that. If you give a relative path to the URL, however, you would need a way to pass in another piece of information to let the command determine what it is relative to, and that is the reason why this parameter exists.

But you _shouldn't_ be making me (or others, for that matter) wonder why and justify it for you. It should be explained in the commit log message.

Mark Levedahl· Mar 4, 2008, 12:39 UTC · re: Junio C Hamano · lore

Re: [PATCH] git-submodule - Allow adding a submodule in-place

On Tue, Mar 4, 2008 at 2:09 AM, Junio C Hamano <gitster@pobox.com> wrote:
>
>  However, this part is not mentioned in the commit log message at all.

...because the code to do the latter part is not a part of the patch, and I failed to edit the documentation patch to remove that other cruft. Will resend tonight when I have a connection that lets me send patches.

Mark
Sven Verdoolaege· Mar 4, 2008, 11:22 UTC · re: Mark Levedahl · lore

Re: [PATCH] git-submodule - Allow adding a submodule in-place

On Mon, Mar 03, 2008 at 09:06:23PM -0500, Mark Levedahl wrote:
Show 26 quoted lines
> @@ -9,17 +9,18 @@ git-submodule - Initialize, update or inspect submodules
>  SYNOPSIS
>  --------
>  [verse]
> -'git-submodule' [--quiet] add [-b branch] [--] <repository> [<path>]
> +'git-submodule' [--quiet] add [-b branch] [-r <remote>] [--] <repository> [<path>]
>  'git-submodule' [--quiet] status [--cached] [--] [<path>...]
> -'git-submodule' [--quiet] [init|update] [--] [<path>...]
> +'git-submodule' [--quiet] [init|update] [-r <remote>] [--] [<path>...]
>  
> @@ -55,6 +56,18 @@ OPTIONS
>  -b, --branch::
>  	Branch of repository to add as submodule.
>  
> +-r remote::
> +	Name of remote to use or define when working with relative submodules
> +	(i.e., submodules whose url is given relative to the top-level
> +	project). If this value is undefined, the top-level project's
> +	branch.<name>.remote is used, and if that is undefined the default
> +	"origin" is used. The remote will be defined in each relative
> +	submodule as needed by appending the relative url to the top level
> +	project's url. This option has no effect upon submodules defined
> +	using an absolute url: such project's are cloned using the default
> +	"origin," and are updated using the submodule's branch.<name>.remote
> +	machinery and defaulting to "origin."
> +
As has been noted by others, these changes don't belong in this commit.

As to the functionality actually provided by this patch, I'm somewhat concerned with encouraging this kind of setup, where the main (and only) copy of your subproject repo is stored inside the working tree.

Ideally (for some at least), switching back to a commit of the superproject from before the subproject was added should remove the subproject from the working tree. This means that the GIT_DIR of the subproject should be stored somewhere under the GIT_DIR of the superproject. There was some talk about doing this about a year ago, but AFAIK, it hasn't gotten implemented yet. It's easier to handle this when adding a subproject that does not already exist in the tree.

Of course, if this feature would ever get implemented, then it would also have to provide an upgrade path from the current setup and that upgrade path would also handle your case. So this is not really an objection, but just a concern.

skimo
Mark Levedahl· Mar 5, 2008, 01:15 UTC · re: Mark Levedahl · lore

When working in top-level project, it is useful to create a new submodule as a git repo in a subdirectory, then add that submodule to top-level in place. This allows "git submodule add <intended url> subdir" to add the existing subdir to the current project. The presumption is the user will later push / clone the subdir to the <intended url> so that future submodule init / updates will work.

Absent this patch, "git submodule add" insists upon cloning the subdir from a repository at the given url, which is fine for adding an existing project in but less useful when adding a new submodule from scratch to an existing project. The former functionality remains, and the clone is attempted if the subdir does not already exist as a valid git repo.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>
---

This eliminates the extraneous documentation of the previous patch that was for functionality unrelated to this topic.

 Documentation/git-submodule.txt |    5 ++-
 git-submodule.sh                |   50 +++++++++++++++++++++++---------------
 2 files changed, 33 insertions(+), 22 deletions(-)
Show changes to 2 files +33 −23

Documentation/git-submodule.txt, git-submodule.sh

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index e818e6e..b4d0160 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -18,8 +18,9 @@ COMMANDS
 --------
 add::
 	Add the given repository as a submodule at the given path
-	to the changeset to be committed next.  In particular, the
-	repository is cloned at the specified path, added to the
+	to the changeset to be committed next.  If path is a valid
+	repository within the project, it is added as is. Otherwise,
+	repository is cloned at the specified path. path is added to the
 	changeset and registered in .gitmodules.   If no path is
 	specified, the path is deduced from the repository specification.
 	If the repository url begins with ./ or ../, it is stored as
diff --git a/git-submodule.sh b/git-submodule.sh
index 67d3224..7171cb6 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -153,20 +153,6 @@ cmd_add()
 		usage
 	fi

-	case "$repo" in
-	./*|../*)
-		# dereference source url relative to parent's url
-		realrepo="$(resolve_relative_url $repo)" ;;
-	*)
-		# Turn the source into an absolute path if
-		# it is local
-		if base=$(get_repo_base "$repo"); then
-			repo="$base"
-		fi
-		realrepo=$repo
-		;;
-	esac
-
 	# Guess path from repo if not specified or strip trailing slashes
 	if test -z "$path"; then
 		path=$(echo "$repo" | sed -e 's|/*$||' -e 's|:*/*\.git$||' -e 's|.*[/:]||g')
@@ -174,15 +160,39 @@ cmd_add()
 		path=$(echo "$path" | sed -e 's|/*$||')
 	fi

-	test -e "$path" &&
-	die "'$path' already exists"
-
 	git ls-files --error-unmatch "$path" > /dev/null 2>&1 &&
 	die "'$path' already exists in the index"

-	module_clone "$path" "$realrepo" || exit
-	(unset GIT_DIR; cd "$path" && git checkout -q ${branch:+-b "$branch" "origin/$branch"}) ||
-	die "Unable to checkout submodule '$path'"
+	# perhaps the path exists and is already a git repo, else clone it
+	if test -e "$path"
+	then
+		if test -d "$path/.git" &&
+		test "$(unset GIT_DIR; cd $path; git rev-parse --git-dir)" = ".git"
+		then
+			echo "Adding existing repo at '$path' to the index"
+		else
+			die "'$path' already exists and is not a valid git repo"
+		fi
+	else
+		case "$repo" in
+		./*|../*)
+			# dereference source url relative to parent's url
+			realrepo="$(resolve_relative_url $repo)" ;;
+		*)
+			# Turn the source into an absolute path if
+			# it is local
+			if base=$(get_repo_base "$repo"); then
+				repo="$base"
+			fi
+			realrepo=$repo
+			;;
+		esac
+
+		module_clone "$path" "$realrepo" || exit
+		(unset GIT_DIR; cd "$path" && git checkout -q ${branch:+-b "$branch" "origin/$branch"}) ||
+		die "Unable to checkout submodule '$path'"
+	fi
+
 	git add "$path" ||
 	die "Failed to add submodule '$path'"

--
1.5.4.3.438.g4c6f8

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