submodule: add 'deinit' command

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 used)
together with their work tree. Fail if the current work tree contains
modifications (unless forced), but don't complain when either the work
tree is already removed or no settings are found in .git/config.

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. Also add the deinit subcommand
to the completion list.

Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

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 the removal,
+use linkgit:git-submodule[1] `deinit` instead.
+
 EXAMPLES
 --------
 `git rm Documentation/\*.txt`::

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] [-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.
@@ -211,8 +225,10 @@ 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

contrib/completion/git-completion.bash

@@ -2176,7 +2176,7 @@ _git_submodule ()
 {
 	__git_has_doubledash && return
 
-	local subcommands="add status init update summary foreach sync"
+	local subcommands="add status init deinit update summary foreach sync"
 	if [ -z "$(__git_find_on_cmdline "$subcommands")" ]; then
 		case "$cur" in
 		--*)

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] [-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>
@@ -515,6 +516,80 @@ cmd_init()
 	done
 }
 
+#
+# Unregister submodules from .git/config and remove their work tree
+#
+# $@ = requested paths (use '.' to deinit all submodules)
+#
+cmd_deinit()
+{
+	# parse $args after "submodule ... deinit".
+	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
+
+		# Remove the submodule work tree (unless the user already did it)
+		if test -d "$sm_path"
+		then
+			# Protect submodules containing a .git directory
+			if test -d "$sm_path/.git"
+			then
+				echo >&2 "$(eval_gettext "Submodule work tree '\$sm_path' contains a .git directory")"
+				die "$(eval_gettext "(use 'rm -rf' if you really want to remove it including all of its history)")"
+			fi
+
+			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" || say "$(eval_gettext "Could not remove submodule work tree '\$sm_path'")"
+		fi
+
+		mkdir "$sm_path" || say "$(eval_gettext "Could not create empty submodule directory '\$sm_path'")"
+
+		# Remove the .git/config entries (unless the user already did it)
+		if test -n "$(git config --get-regexp submodule."$name\.")"
+		then
+			# Remove the whole section so we have a clean state when
+			# the user later decides to init this submodule again
+			url=$(git config submodule."$name".url)
+			git config --remove-section submodule."$name" 2>/dev/null &&
+			say "$(eval_gettext "Submodule '\$name' (\$url) unregistered for path '\$sm_path'")"
+		fi
+	done
+}
+
 #
 # Update each submodule path to correct revision, using clone and checkout as needed
 #
@@ -1108,7 +1183,7 @@ 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)

t/t7400-submodule-basic.sh

@@ -756,4 +756,104 @@ test_expect_success 'submodule add with an existing name fails unless forced' '
 	)
 '
 
+test_expect_success 'set up a second submodule' '
+	git submodule add ./init2 example2 &&
+	git commit -m "submodule example2 added"
+'
+
+test_expect_success 'submodule deinit should remove the whole submodule section from .git/config' '
+	git config submodule.example.foo bar &&
+	git config submodule.example2.frotz nitfol &&
+	git submodule deinit init &&
+	test -z "$(git config --get-regexp "submodule\.example\.")" &&
+	test -n "$(git config --get-regexp "submodule\.example2\.")" &&
+	test -f example2/.git &&
+	rmdir init
+'
+
+test_expect_success 'submodule deinit . deinits all initialized submodules' '
+	git submodule update --init &&
+	git config submodule.example.foo bar &&
+	git config submodule.example2.frotz nitfol &&
+	test_must_fail git submodule deinit &&
+	git submodule deinit . &&
+	test -z "$(git config --get-regexp "submodule\.example\.")" &&
+	test -z "$(git config --get-regexp "submodule\.example2\.")" &&
+	rmdir init example2
+'
+
+test_expect_success 'submodule deinit deinits a submodule when its work tree is missing or empty' '
+	git submodule update --init &&
+	rm -rf init example2/* example2/.git &&
+	git submodule deinit init example2 &&
+	test -z "$(git config --get-regexp "submodule\.example\.")" &&
+	test -z "$(git config --get-regexp "submodule\.example2\.")" &&
+	rmdir init
+'
+
+test_expect_success 'submodule deinit fails when the submodule contains modifications unless forced' '
+	git submodule update --init &&
+	echo X >>init/s &&
+	test_must_fail git submodule deinit init &&
+	test -n "$(git config --get-regexp "submodule\.example\.")" &&
+	test -f example2/.git &&
+	git submodule deinit -f init &&
+	test -z "$(git config --get-regexp "submodule\.example\.")" &&
+	rmdir init
+'
+
+test_expect_success 'submodule deinit fails when the submodule contains untracked files unless forced' '
+	git submodule update --init &&
+	echo X >>init/untracked &&
+	test_must_fail git submodule deinit init &&
+	test -n "$(git config --get-regexp "submodule\.example\.")" &&
+	test -f example2/.git &&
+	git submodule deinit -f init &&
+	test -z "$(git config --get-regexp "submodule\.example\.")" &&
+	rmdir init
+'
+
+test_expect_success 'submodule deinit fails when the submodule HEAD does not match unless forced' '
+	git submodule update --init &&
+	(
+		cd init &&
+		git checkout HEAD^
+	) &&
+	test_must_fail git submodule deinit init &&
+	test -n "$(git config --get-regexp "submodule\.example\.")" &&
+	test -f example2/.git &&
+	git submodule deinit -f init &&
+	test -z "$(git config --get-regexp "submodule\.example\.")" &&
+	rmdir init
+'
+
+test_expect_success 'submodule deinit is silent when 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 ! "Submodule .example. (.*) unregistered for path .init" actual &&
+	git submodule deinit . >actual &&
+	test_i18ngrep ! "Submodule .example. (.*) unregistered for path .init" actual &&
+	test_i18ngrep "Submodule .example2. (.*) unregistered for path .example2" actual &&
+	git submodule deinit . >actual &&
+	test_i18ngrep ! "Submodule .example. (.*) unregistered for path .init" actual &&
+	test_i18ngrep ! "Submodule .example2. (.*) unregistered for path .example2" actual &&
+	rmdir init example2
+'
+
+test_expect_success 'submodule deinit fails when submodule has a .git directory even when forced' '
+	git submodule update --init &&
+	(
+		cd init &&
+		rm .git &&
+		cp -R ../.git/modules/example .git &&
+		GIT_WORK_TREE=. git config --unset core.worktree
+	) &&
+	test_must_fail git submodule deinit init &&
+	test_must_fail git submodule deinit -f init &&
+	test -d init/.git &&
+	test -n "$(git config --get-regexp "submodule\.example\.")"
+'
+
 test_done