[PATCH 1/4] git submodule: Teach add to accept --group

[Stefan Beller <sbeller@google.com>]

When adding new submodules, you can specify the
group(s) the submodule belongs to by giving one or more
--group arguments. This will record each group in the
.gitmodules file as a value of the key
"submodule.$NAME.group".

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 Documentation/git-submodule.txt |  8 +++++++-
 git-submodule.sh                | 15 +++++++++++++++
 t/t7400-submodule-basic.sh      | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index 13adebf..135c739 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -9,7 +9,7 @@ git-submodule - Initialize, update or inspect submodules
 SYNOPSIS
 --------
 [verse]
-'git submodule' [--quiet] add [-b <branch>] [-f|--force] [--name <name>]
+'git submodule' [--quiet] add [-b <branch>] [-f|--force] [-g <group>][--name <name>]
 	      [--reference <repository>] [--depth <depth>] [--] <repository> [<path>]
 'git submodule' [--quiet] status [--cached] [--recursive] [--] [<path>...]
 'git submodule' [--quiet] init [--] [<path>...]
@@ -59,6 +59,9 @@ instead of treating the other project as a submodule. Directories
 that come from both projects can be cloned and checked out as a whole
 if you choose to go that route.
 
+If you manage a large set of submodules, but do not require all of them
+to be checked out, you should look into the submodule groups feature.
+
 COMMANDS
 --------
 add::
@@ -101,6 +104,9 @@ is the superproject and submodule repositories will be kept
 together in the same relative location, and only the
 superproject's URL needs to be provided: git-submodule will correctly
 locate the submodule using the relative URL in .gitmodules.
++
+If at least one group argument was given, all groups are recorded in the
+.gitmodules file in the groups field.
 
 status::
 	Show the status of the submodules. This will print the SHA-1 of the
diff --git a/git-submodule.sh b/git-submodule.sh
index 6fce0dc..ab0f209 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -130,6 +130,7 @@ cmd_add()
 {
 	# parse $args after "submodule ... add".
 	reference_path=
+	submodule_groups=
 	while test $# -ne 0
 	do
 		case "$1" in
@@ -165,6 +166,10 @@ cmd_add()
 		--depth=*)
 			depth=$1
 			;;
+		-g|--group)
+			submodule_groups=${submodule_groups:+${submodule_groups};}"$2"
+			shift
+			;;
 		--)
 			shift
 			break
@@ -292,6 +297,16 @@ Use -f if you really want to add it." >&2
 
 	git config -f .gitmodules submodule."$sm_name".path "$sm_path" &&
 	git config -f .gitmodules submodule."$sm_name".url "$repo" &&
+	if test -n "$submodule_groups"
+	then
+		OIFS=$IFS
+		IFS=';'
+		for group in $submodule_groups
+		do
+			git config --add -f .gitmodules submodule."$sm_name".group "${group}"
+		done
+		IFS=$OIFS
+	fi &&
 	if test -n "$branch"
 	then
 		git config -f .gitmodules submodule."$sm_name".branch "$branch"
diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index 5991e3c..b468278 100755
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -986,6 +986,7 @@ test_expect_success 'submodule with UTF-8 name' '
 '
 
 test_expect_success 'submodule add clone shallow submodule' '
+	test_when_finished "rm -rf super" &&
 	mkdir super &&
 	pwd=$(pwd) &&
 	(
@@ -999,5 +1000,36 @@ test_expect_success 'submodule add clone shallow submodule' '
 	)
 '
 
+test_expect_success 'submodule add records a group' '
+	test_when_finished "rm -rf super" &&
+	mkdir super &&
+	pwd=$(pwd) &&
+	(
+		cd super &&
+		git init &&
+		git submodule add --group groupA file://"$pwd"/example2 submodule &&
+		git config -f .gitmodules submodule."submodule".group >actual &&
+		echo groupA >expected &&
+		test_cmp expected actual
+	)
+'
+
+cat >expected <<-EOF
+groupA
+groupB
+EOF
+
+test_expect_success 'submodule add records groups' '
+	test_when_finished "rm -rf super" &&
+	mkdir super &&
+	pwd=$(pwd) &&
+	(
+		cd super &&
+		git init &&
+		git submodule add --group groupA -g groupB file://"$pwd"/example2 submodule &&
+		git config --get-all -f .gitmodules submodule."submodule".group >../actual
+	) &&
+	test_cmp expected actual
+'
 
 test_done
-- 
2.7.0.rc0.41.g89994f2.dirty