submodule: drop the top-level requirement

Use the new rev-parse --prefix option to process all paths given to the
submodule command, dropping the requirement that it be run from the
top-level of the repository.

Since the interpretation of a relative submodule URL depends on whether
or not "remote.origin.url" is configured, explicitly block relative URLs
in "git submodule add" when not at the top level of the working tree.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: johnkeeping

git-submodule.sh

@@ -14,10 +14,13 @@ USAGE="[--quiet] add [-b <branch>] [-f|--force] [--name <name>] [--reference <re
    or: $dashless [--quiet] foreach [--recursive] <command>
    or: $dashless [--quiet] sync [--recursive] [--] [<path>...]"
 OPTIONS_SPEC=
+SUBDIRECTORY_OK=Yes
 . git-sh-setup
 . git-sh-i18n
 . git-parse-remote
 require_work_tree
+wt_prefix=$(git rev-parse --show-prefix)
+cd_to_toplevel
 
 command=
 branch=
@@ -106,12 +109,48 @@ resolve_relative_url ()
 	echo "${is_relative:+${up_path}}${remoteurl#./}"
 }
 
+# Resolve a path to be relative to another path.  This is intended for
+# converting submodule paths when git-submodule is run in a subdirectory
+# and only handles paths where the directory separator is '/'.
+#
+# The output is the first argument as a path relative to the second argument,
+# which defaults to $wt_prefix if it is omitted.
+relative_path ()
+{
+	local target curdir result
+	target=$1
+	curdir=${2-$wt_prefix}
+	curdir=${curdir%/}
+	result=
+
+	while test -n "$curdir"
+	do
+		case "$target" in
+		"$curdir/"*)
+			target=${target#"$curdir"/}
+			break
+			;;
+		esac
+
+		result="${result}../"
+		if test "$curdir" = "${curdir%/*}"
+		then
+			curdir=
+		else
+			curdir="${curdir%/*}"
+		fi
+	done
+
+	echo "$result$target"
+}
+
 #
 # Get submodule info for registered submodules
 # $@ = path to limit submodule list
 #
 module_list()
 {
+	eval "set $(git rev-parse --sq --prefix "$wt_prefix" -- "$@")"
 	(
 		git ls-files --error-unmatch --stage -- "$@" ||
 		echo "unmatched pathspec exists"
@@ -282,6 +321,7 @@ isnumber()
 cmd_add()
 {
 	# parse $args after "submodule ... add".
+	reference_path=
 	while test $# -ne 0
 	do
 		case "$1" in
@@ -298,11 +338,11 @@ cmd_add()
 			;;
 		--reference)
 			case "$2" in '') usage ;; esac
-			reference="--reference=$2"
+			reference_path=$2
 			shift
 			;;
 		--reference=*)
-			reference="$1"
+			reference_path="${1#--reference=}"
 			;;
 		--name)
 			case "$2" in '') usage ;; esac
@@ -323,6 +363,14 @@ cmd_add()
 		shift
 	done
 
+	if test -n "$reference_path"
+	then
+		is_absolute_path "$reference_path" ||
+		reference_path="$wt_prefix$reference_path"
+
+		reference="--reference=$reference_path"
+	fi
+
 	repo=$1
 	sm_path=$2
 
@@ -335,9 +383,14 @@ cmd_add()
 		usage
 	fi
 
+	is_absolute_path "$sm_path" || sm_path="$wt_prefix$sm_path"
+
 	# assure repo is absolute or relative to parent
 	case "$repo" in
 	./*|../*)
+		test -z "$wt_prefix" ||
+		die "$(gettext "Relative path can only be used from the toplevel of the working tree")"
+
 		# dereference source url relative to parent's url
 		realrepo=$(resolve_relative_url "$repo") || exit
 		;;
@@ -471,21 +524,23 @@ cmd_foreach()
 		die_if_unmatched "$mode"
 		if test -e "$sm_path"/.git
 		then
-			say "$(eval_gettext "Entering '\$prefix\$sm_path'")"
+			displaypath=$(relative_path "$sm_path")
+			say "$(eval_gettext "Entering '\$prefix\$displaypath'")"
 			name=$(module_name "$sm_path")
 			(
 				prefix="$prefix$sm_path/"
 				clear_local_git_env
-				# we make $path available to scripts ...
-				path=$sm_path
 				cd "$sm_path" &&
+				sm_path=$(relative_path "$sm_path") &&
+				# we make $path available to scripts ...
+				path=$sm_path &&
 				eval "$@" &&
 				if test -n "$recursive"
 				then
 					cmd_foreach "--recursive" "$@"
 				fi
 			) <&3 3<&- ||
-			die "$(eval_gettext "Stopping at '\$prefix\$sm_path'; script returned non-zero status.")"
+			die "$(eval_gettext "Stopping at '\$prefix\$displaypath'; script returned non-zero status.")"
 		fi
 	done
 }
@@ -524,12 +579,14 @@ cmd_init()
 		die_if_unmatched "$mode"
 		name=$(module_name "$sm_path") || exit
 
+		displaypath=$(relative_path "$sm_path")
+
 		# Copy url setting when it is not set yet
 		if test -z "$(git config "submodule.$name.url")"
 		then
 			url=$(git config -f .gitmodules submodule."$name".url)
 			test -z "$url" &&
-			die "$(eval_gettext "No url found for submodule path '\$sm_path' in .gitmodules")"
+			die "$(eval_gettext "No url found for submodule path '\$displaypath' in .gitmodules")"
 
 			# Possibly a url relative to parent
 			case "$url" in
@@ -538,17 +595,17 @@ cmd_init()
 				;;
 			esac
 			git config submodule."$name".url "$url" ||
-			die "$(eval_gettext "Failed to register url for submodule path '\$sm_path'")"
+			die "$(eval_gettext "Failed to register url for submodule path '\$displaypath'")"
 
-			say "$(eval_gettext "Submodule '\$name' (\$url) registered for path '\$sm_path'")"
+			say "$(eval_gettext "Submodule '\$name' (\$url) registered for path '\$displaypath'")"
 		fi
 
 		# Copy "update" setting when it is not set yet
 		upd="$(git config -f .gitmodules submodule."$name".update)"
 		test -z "$upd" ||
 		test -n "$(git config submodule."$name".update)" ||
 		git config submodule."$name".update "$upd" ||
-		die "$(eval_gettext "Failed to register update mode for submodule path '\$sm_path'")"
+		die "$(eval_gettext "Failed to register update mode for submodule path '\$displaypath'")"
 	done
 }
 
@@ -594,27 +651,29 @@ cmd_deinit()
 		die_if_unmatched "$mode"
 		name=$(module_name "$sm_path") || exit
 
+		displaypath=$(relative_path "$sm_path")
+
 		# 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 "$(eval_gettext "Submodule work tree '\$sm_path' contains a .git directory")"
+				echo >&2 "$(eval_gettext "Submodule work tree '\$displaypath' 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 "$force"
 			then
 				git rm -qn "$sm_path" ||
-				die "$(eval_gettext "Submodule work tree '\$sm_path' contains local modifications; use '-f' to discard them")"
+				die "$(eval_gettext "Submodule work tree '\$displaypath' contains local modifications; use '-f' to discard them")"
 			fi
 			rm -rf "$sm_path" &&
-			say "$(eval_gettext "Cleared directory '\$sm_path'")" ||
-			say "$(eval_gettext "Could not remove submodule work tree '\$sm_path'")"
+			say "$(eval_gettext "Cleared directory '\$displaypath'")" ||
+			say "$(eval_gettext "Could not remove submodule work tree '\$displaypath'")"
 		fi
 
-		mkdir "$sm_path" || say "$(eval_gettext "Could not create empty submodule directory '\$sm_path'")"
+		mkdir "$sm_path" || say "$(eval_gettext "Could not create empty submodule directory '\$displaypath'")"
 
 		# Remove the .git/config entries (unless the user already did it)
 		if test -n "$(git config --get-regexp submodule."$name\.")"
@@ -623,7 +682,7 @@ cmd_deinit()
 			# 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'")"
+			say "$(eval_gettext "Submodule '\$name' (\$url) unregistered for path '\$displaypath'")"
 		fi
 	done
 }
@@ -717,9 +776,11 @@ cmd_update()
 			update_module=$(git config submodule."$name".update)
 		fi
 
+		displaypath=$(relative_path "$prefix$sm_path")
+
 		if test "$update_module" = "none"
 		then
-			echo "Skipping submodule '$prefix$sm_path'"
+			echo "Skipping submodule '$displaypath'"
 			continue
 		fi
 
@@ -728,7 +789,7 @@ cmd_update()
 			# Only mention uninitialized submodules when its
 			# path have been specified
 			test "$#" != "0" &&
-			say "$(eval_gettext "Submodule path '\$prefix\$sm_path' not initialized
+			say "$(eval_gettext "Submodule path '\$displaypath' not initialized
 Maybe you want to use 'update --init'?")"
 			continue
 		fi
@@ -741,7 +802,7 @@ Maybe you want to use 'update --init'?")"
 		else
 			subsha1=$(clear_local_git_env; cd "$sm_path" &&
 				git rev-parse --verify HEAD) ||
-			die "$(eval_gettext "Unable to find current revision in submodule path '\$prefix\$sm_path'")"
+			die "$(eval_gettext "Unable to find current revision in submodule path '\$displaypath'")"
 		fi
 
 		if test -n "$remote"
@@ -774,7 +835,7 @@ Maybe you want to use 'update --init'?")"
 				(clear_local_git_env; cd "$sm_path" &&
 					( (rev=$(git rev-list -n 1 $sha1 --not --all 2>/dev/null) &&
 					 test -z "$rev") || git-fetch)) ||
-				die "$(eval_gettext "Unable to fetch in submodule path '\$prefix\$sm_path'")"
+				die "$(eval_gettext "Unable to fetch in submodule path '\$displaypath'")"
 			fi
 
 			# Is this something we just cloned?
@@ -788,20 +849,20 @@ Maybe you want to use 'update --init'?")"
 			case "$update_module" in
 			rebase)
 				command="git rebase"
-				die_msg="$(eval_gettext "Unable to rebase '\$sha1' in submodule path '\$prefix\$sm_path'")"
-				say_msg="$(eval_gettext "Submodule path '\$prefix\$sm_path': rebased into '\$sha1'")"
+				die_msg="$(eval_gettext "Unable to rebase '\$sha1' in submodule path '\$displaypath'")"
+				say_msg="$(eval_gettext "Submodule path '\$displaypath': rebased into '\$sha1'")"
 				must_die_on_failure=yes
 				;;
 			merge)
 				command="git merge"
-				die_msg="$(eval_gettext "Unable to merge '\$sha1' in submodule path '\$prefix\$sm_path'")"
-				say_msg="$(eval_gettext "Submodule path '\$prefix\$sm_path': merged in '\$sha1'")"
+				die_msg="$(eval_gettext "Unable to merge '\$sha1' in submodule path '\$displaypath'")"
+				say_msg="$(eval_gettext "Submodule path '\$displaypath': merged in '\$sha1'")"
 				must_die_on_failure=yes
 				;;
 			*)
 				command="git checkout $subforce -q"
-				die_msg="$(eval_gettext "Unable to checkout '\$sha1' in submodule path '\$prefix\$sm_path'")"
-				say_msg="$(eval_gettext "Submodule path '\$prefix\$sm_path': checked out '\$sha1'")"
+				die_msg="$(eval_gettext "Unable to checkout '\$sha1' in submodule path '\$displaypath'")"
+				say_msg="$(eval_gettext "Submodule path '\$displaypath': checked out '\$sha1'")"
 				;;
 			esac
 
@@ -828,7 +889,7 @@ Maybe you want to use 'update --init'?")"
 			res=$?
 			if test $res -gt 0
 			then
-				die_msg="$(eval_gettext "Failed to recurse into submodule path '\$prefix\$sm_path'")"
+				die_msg="$(eval_gettext "Failed to recurse into submodule path '\$displaypath'")"
 				if test $res -eq 1
 				then
 					err="${err};$die_msg"
@@ -942,6 +1003,7 @@ cmd_summary() {
 	fi
 
 	cd_to_toplevel
+	eval "set $(git rev-parse --sq --prefix "$wt_prefix" -- "$@")"
 	# Get modified modules cared by user
 	modules=$(git $diff_cmd $cached --ignore-submodules=dirty --raw $head -- "$@" |
 		sane_egrep '^:([0-7]* )?160000' |
@@ -991,16 +1053,18 @@ cmd_summary() {
 		! GIT_DIR="$name/.git" git-rev-parse -q --verify $sha1_dst^0 >/dev/null &&
 		missing_dst=t
 
+		display_name=$(relative_path "$name")
+
 		total_commits=
 		case "$missing_src,$missing_dst" in
 		t,)
-			errmsg="$(eval_gettext "  Warn: \$name doesn't contain commit \$sha1_src")"
+			errmsg="$(eval_gettext "  Warn: \$display_name doesn't contain commit \$sha1_src")"
 			;;
 		,t)
-			errmsg="$(eval_gettext "  Warn: \$name doesn't contain commit \$sha1_dst")"
+			errmsg="$(eval_gettext "  Warn: \$display_name doesn't contain commit \$sha1_dst")"
 			;;
 		t,t)
-			errmsg="$(eval_gettext "  Warn: \$name doesn't contain commits \$sha1_src and \$sha1_dst")"
+			errmsg="$(eval_gettext "  Warn: \$display_name doesn't contain commits \$sha1_src and \$sha1_dst")"
 			;;
 		*)
 			errmsg=
@@ -1029,12 +1093,12 @@ cmd_summary() {
 			submodule="$(gettext "submodule")"
 			if test $mod_dst = 160000
 			then
-				echo "* $name $sha1_abbr_src($blob)->$sha1_abbr_dst($submodule)$total_commits:"
+				echo "* $display_name $sha1_abbr_src($blob)->$sha1_abbr_dst($submodule)$total_commits:"
 			else
-				echo "* $name $sha1_abbr_src($submodule)->$sha1_abbr_dst($blob)$total_commits:"
+				echo "* $display_name $sha1_abbr_src($submodule)->$sha1_abbr_dst($blob)$total_commits:"
 			fi
 		else
-			echo "* $name $sha1_abbr_src...$sha1_abbr_dst$total_commits:"
+			echo "* $display_name $sha1_abbr_src...$sha1_abbr_dst$total_commits:"
 		fi
 		if test -n "$errmsg"
 		then
@@ -1118,7 +1182,7 @@ cmd_status()
 		die_if_unmatched "$mode"
 		name=$(module_name "$sm_path") || exit
 		url=$(git config submodule."$name".url)
-		displaypath="$prefix$sm_path"
+		displaypath=$(relative_path "$prefix$sm_path")
 		if test "$stage" = U
 		then
 			say "U$sha1 $displaypath"
@@ -1213,7 +1277,8 @@ cmd_sync()
 
 		if git config "submodule.$name.url" >/dev/null 2>/dev/null
 		then
-			say "$(eval_gettext "Synchronizing submodule url for '\$prefix\$sm_path'")"
+			displaypath=$(relative_path "$prefix$sm_path")
+			say "$(eval_gettext "Synchronizing submodule url for '\$displaypath'")"
 			git config submodule."$name".url "$super_config_url"
 
 			if test -e "$sm_path"/.git