[PATCH v3] submodule: add 'deinit' command

[Jens Lehmann <Jens.Lehmann@web.de>]

With "git submodule init" the user is able to tell git he cares about one
or more submodules and wants to have it populated on the next call to "git
submodule update". But currently there is no easy way he could tell git he
does not care about a submodule anymore and wants to get rid of his local
work tree (except he knows a lot about submodule internals and removes the
"submodule.$name.url" setting from .git/config together with the work tree
himself).

Help those users by providing a 'deinit' command. This removes the whole
submodule.<name> section from .git/config either for the given
submodule(s) (or for all those which have been initialized if '.' is
given). Fail if the current work tree contains modifications unless
forced. Complain when for a submodule given on the command line the url
setting can't be found in .git/config, but nonetheless don't fail.

Add tests and link the man pages of "git submodule deinit" and "git rm"
to assist the user in deciding whether removing or unregistering the
submodule is the right thing to do for him.

Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
---

Ok, here is the reroll following the discussion in $gmane/212884.

Changes since v2 are:
- deinit always needs an argument; if the user wants to deinit all initialized
  submodules he can use "." (and we tell him that when failing without any
  arguments).
- We also remove the work tree of the submodule. When it contains local changes
  (tested with "git rm -n") this fails unless forced.


 Documentation/git-rm.txt        |  4 +++
 Documentation/git-submodule.txt | 18 ++++++++++-
 git-submodule.sh                | 70 ++++++++++++++++++++++++++++++++++++++++-
 t/t7400-submodule-basic.sh      | 24 ++++++++++++++
 4 files changed, 114 insertions(+), 2 deletions(-)

diff --git a/Documentation/git-rm.txt b/Documentation/git-rm.txt
index 262436b..8ae72f7 100644
--- a/Documentation/git-rm.txt
+++ b/Documentation/git-rm.txt
@@ -149,6 +149,10 @@ files that aren't ignored are present in the submodules work tree.
 Ignored files are deemed expendable and won't stop a submodule's work
 tree from being removed.

+If you only want to remove the local checkout of a submodule from your
+work tree without committing that use linkgit:git-submodule[1] `deinit`
+instead.
+
 EXAMPLES
 --------
 `git rm Documentation/\*.txt`::
diff --git a/Documentation/git-submodule.txt b/Documentation/git-submodule.txt
index b1996f1..9a20e1d 100644
--- a/Documentation/git-submodule.txt
+++ b/Documentation/git-submodule.txt
@@ -13,6 +13,7 @@ SYNOPSIS
 	      [--reference <repository>] [--] <repository> [<path>]
 'git submodule' [--quiet] status [--cached] [--recursive] [--] [<path>...]
 'git submodule' [--quiet] init [--] [<path>...]
+'git submodule' [--quiet] deinit [-f|--force] [--] <path>...
 'git submodule' [--quiet] update [--init] [--remote] [-N|--no-fetch] [--rebase]
 	      [--reference <repository>] [--merge] [--recursive] [--] [<path>...]
 'git submodule' [--quiet] summary [--cached|--files] [(-n|--summary-limit) <n>]
@@ -134,6 +135,19 @@ init::
 	the explicit 'init' step if you do not intend to customize
 	any submodule locations.

+deinit::
+	Unregister the given submodules, i.e. remove the whole
+	`submodule.$name` section from .git/config together with their work
+	tree. Further calls to `git submodule update`, `git submodule foreach`
+	and `git submodule sync` will skip any unregistered submodules until
+	they are initialized again, so use this command if you don't want to
+	have a local checkout of the submodule in your work tree anymore. If
+	you really want to remove a submodule from the repository and commit
+	that use linkgit:git-rm[1] instead.
++
+If `--force` is specified, the submodule's work tree will be removed even if
+it contains local modifications.
+
 update::
 	Update the registered submodules, i.e. clone missing submodules and
 	checkout the commit specified in the index of the containing repository.
@@ -213,8 +227,10 @@ OPTIONS

 -f::
 --force::
-	This option is only valid for add and update commands.
+	This option is only valid for add, deinit and update commands.
 	When running add, allow adding an otherwise ignored submodule path.
+	When running deinit the submodule work trees will be removed even if
+	they contain local changes.
 	When running update, throw away local changes in submodules when
 	switching to a different commit; and always run a checkout operation
 	in the submodule, even if the commit listed in the index of the
diff --git a/git-submodule.sh b/git-submodule.sh
index 22ec5b6..e01f6b5 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -8,6 +8,7 @@ dashless=$(basename "$0" | sed -e 's/-/ /')
 USAGE="[--quiet] add [-b <branch>] [-f|--force] [--name <name>] [--reference <repository>] [--] <repository> [<path>]
    or: $dashless [--quiet] status [--cached] [--recursive] [--] [<path>...]
    or: $dashless [--quiet] init [--] [<path>...]
+   or: $dashless [--quiet] deinit [-f|--force] [--] <path>...
    or: $dashless [--quiet] update [--init] [--remote] [-N|--no-fetch] [-f|--force] [--rebase] [--reference <repository>] [--merge] [--recursive] [--] [<path>...]
    or: $dashless [--quiet] summary [--cached|--files] [--summary-limit <n>] [commit] [--] [<path>...]
    or: $dashless [--quiet] foreach [--recursive] <command>
@@ -547,6 +548,73 @@ cmd_init()
 }

 #
+# Unregister submodules from .git/config and remove their work tree
+#
+# $@ = requested paths (use '.' to deinit all submodules)
+#
+cmd_deinit()
+{
+	# parse $args after "submodule ... init".
+	while test $# -ne 0
+	do
+		case "$1" in
+		-f|--force)
+			force=$1
+			;;
+		-q|--quiet)
+			GIT_QUIET=1
+			;;
+		--)
+			shift
+			break
+			;;
+		-*)
+			usage
+			;;
+		*)
+			break
+			;;
+		esac
+		shift
+	done
+
+	if test "$#" == "0"
+	then
+		die "$(eval_gettext "Use '.' if you really want to deinitialize all submodules")"
+	fi
+
+	module_list "$@" |
+	while read mode sha1 stage sm_path
+	do
+		die_if_unmatched "$mode"
+		name=$(module_name "$sm_path") || exit
+		url=$(git config submodule."$name".url)
+		if test -z "$url"
+		then
+			# Only mention uninitialized submodules when its
+			# path have been specified
+			test "$@" != "." &&
+			say "$(eval_gettext "No url found for submodule path '\$sm_path' in .git/config")"
+			continue
+		fi
+
+		# Remove the submodule work tree
+		if test -z $force
+		then
+			git rm -n "$sm_path" ||
+			die "$(eval_gettext "Submodule work tree $sm_path contains local modifications, use '-f' to discard them")"
+		fi
+		rm -rf "$sm_path"
+		mkdir "$sm_path"
+
+		# Remove the whole section so we have a clean state when the
+		# user later decides to init this submodule again
+		git config --remove-section submodule."$name" &&
+		say "$(eval_gettext "Submodule '\$name' (\$url) unregistered for path '\$sm_path'")"
+	done
+}
+
+#
 # Update each submodule path to correct revision, using clone and checkout as needed
 #
 # $@ = requested paths (default to all)
@@ -1157,7 +1225,7 @@ cmd_sync()
 while test $# != 0 && test -z "$command"
 do
 	case "$1" in
-	add | foreach | init | update | status | summary | sync)
+	add | foreach | init | deinit | update | status | summary | sync)
 		command=$1
 		;;
 	-q|--quiet)
diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index 2683cba..34d8274 100755
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -757,4 +757,28 @@ test_expect_success 'submodule add with an existing name fails unless forced' '
 	)
 '

+test_expect_success 'submodule deinit should remove the whole submodule section from .git/config' '
+	git config submodule.example.foo bar &&
+	git submodule deinit init &&
+	test -z "$(git config submodule.example.url)" &&
+	test -z "$(git config submodule.example.foo)"
+'
+
+test_expect_success 'submodule deinit . deinits all initialized submodules' '
+	git submodule update --init &&
+	git config submodule.example.foo bar &&
+	test_must_fail git submodule deinit &&
+	git submodule deinit . &&
+	test -z "$(git config submodule.example.url)" &&
+	test -z "$(git config submodule.example.foo)"
+'
+
+test_expect_success 'submodule deinit complains when explicitly used on an uninitialized submodule' '
+	git submodule update --init &&
+	git submodule deinit init >actual &&
+	test_i18ngrep "Submodule .example. (.*) unregistered for path .init" actual
+	git submodule deinit init >actual &&
+	test_i18ngrep "No url found for submodule path .init. in .git/config" actual
+'
+
 test_done
-- 
1.8.1.2.460.gae7a4e0