subtree: be stricter about validating flags

Don't silently ignore a flag that's invalid for a given subcommand.  The
user expected it to do something; we should tell the user that they are
mistaken, instead of surprising the user.

It could be argued that this change might break existing users.  I'd
argue that those existing users are already broken, and they just don't
know it.  Let them know that they're broken.

Signed-off-by: Luke Shumaker <lukeshu@datawire.io>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 175 insertions, 25 deletions

diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
index 9e4d9a0619..b06782bc79 100755
--- a/contrib/subtree/git-subtree.sh
+++ b/contrib/subtree/git-subtree.sh
@@ -44,17 +44,6 @@ squash        merge subtree changes as a single commit
 m,message=    use the given message as the commit message for the merge commit
 "
 
-arg_debug=
-arg_command=
-arg_prefix=
-arg_split_branch=
-arg_split_onto=
-arg_split_rejoin=
-arg_split_ignore_joins=
-arg_split_annotate=
-arg_addmerge_squash=
-arg_addmerge_message=
-
 indent=0
 
 # Usage: debug [MSG...]
@@ -106,10 +95,61 @@ main () {
 	then
 		set -- -h
 	fi
-	eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
+	set_args="$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
+	eval "$set_args"
 	. git-sh-setup
 	require_work_tree
 
+	# First figure out the command and whether we use --rejoin, so
+	# that we can provide more helpful validation when we do the
+	# "real" flag parsing.
+	arg_split_rejoin=
+	allow_split=
+	allow_addmerge=
+	while test $# -gt 0
+	do
+		opt="$1"
+		shift
+		case "$opt" in
+			--annotate|-b|-P|-m|--onto)
+				shift
+				;;
+			--rejoin)
+				arg_split_rejoin=1
+				;;
+			--no-rejoin)
+				arg_split_rejoin=
+				;;
+			--)
+				break
+				;;
+		esac
+	done
+	arg_command=$1
+	case "$arg_command" in
+	add|merge|pull)
+		allow_addmerge=1
+		;;
+	split|push)
+		allow_split=1
+		allow_addmerge=$arg_split_rejoin
+		;;
+	*)
+		die "Unknown command '$arg_command'"
+		;;
+	esac
+	# Reset the arguments array for "real" flag parsing.
+	eval "$set_args"
+
+	# Begin "real" flag parsing.
+	arg_debug=
+	arg_prefix=
+	arg_split_branch=
+	arg_split_onto=
+	arg_split_ignore_joins=
+	arg_split_annotate=
+	arg_addmerge_squash=
+	arg_addmerge_message=
 	while test $# -gt 0
 	do
 		opt="$1"
@@ -123,13 +163,16 @@ main () {
 			arg_debug=1
 			;;
 		--annotate)
+			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			arg_split_annotate="$1"
 			shift
 			;;
 		--no-annotate)
+			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			arg_split_annotate=
 			;;
 		-b)
+			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			arg_split_branch="$1"
 			shift
 			;;
@@ -138,6 +181,7 @@ main () {
 			shift
 			;;
 		-m)
+			test -n "$allow_addmerge" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			arg_addmerge_message="$1"
 			shift
 			;;
@@ -145,28 +189,34 @@ main () {
 			arg_prefix=
 			;;
 		--onto)
+			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			arg_split_onto="$1"
 			shift
 			;;
 		--no-onto)
+			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			arg_split_onto=
 			;;
 		--rejoin)
-			arg_split_rejoin=1
+			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			;;
 		--no-rejoin)
-			arg_split_rejoin=
+			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			;;
 		--ignore-joins)
+			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			arg_split_ignore_joins=1
 			;;
 		--no-ignore-joins)
+			test -n "$allow_split" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			arg_split_ignore_joins=
 			;;
 		--squash)
+			test -n "$allow_addmerge" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			arg_addmerge_squash=1
 			;;
 		--no-squash)
+			test -n "$allow_addmerge" || die "The '$opt' flag does not make sense with 'git subtree $arg_command'."
 			arg_addmerge_squash=
 			;;
 		--)
@@ -177,19 +227,8 @@ main () {
 			;;
 		esac
 	done
-
-	arg_command="$1"
 	shift
 
-	case "$arg_command" in
-	add|merge|pull|split|push)
-		:
-		;;
-	*)
-		die "Unknown command '$arg_command'"
-		;;
-	esac
-
 	if test -z "$arg_prefix"
 	then
 		die "You must provide the --prefix option."
diff --git a/contrib/subtree/t/t7900-subtree.sh b/contrib/subtree/t/t7900-subtree.sh
index d7ad6ffff0..4153b65321 100755
--- a/contrib/subtree/t/t7900-subtree.sh
+++ b/contrib/subtree/t/t7900-subtree.sh
@@ -33,6 +33,12 @@ test_create_commit () (
 	git commit -m "$commit" || error "Could not commit"
 )
 
+test_wrong_flag() {
+	test_must_fail "$@" >out 2>err &&
+	test_must_be_empty out &&
+	grep "flag does not make sense with" err
+}
+
 last_commit_subject () {
 	git log --pretty=format:%s -1
 }
@@ -72,6 +78,22 @@ test_expect_success 'no pull from non-existent subtree' '
 	)
 '
 
+test_expect_success 'add rejects flags for split' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		test_wrong_flag git subtree add --prefix="sub dir" --annotate=foo FETCH_HEAD &&
+		test_wrong_flag git subtree add --prefix="sub dir" --branch=foo FETCH_HEAD &&
+		test_wrong_flag git subtree add --prefix="sub dir" --ignore-joins FETCH_HEAD &&
+		test_wrong_flag git subtree add --prefix="sub dir" --onto=foo FETCH_HEAD &&
+		test_wrong_flag git subtree add --prefix="sub dir" --rejoin FETCH_HEAD
+	)
+'
+
 test_expect_success 'add subproj as subtree into sub dir/ with --prefix' '
 	subtree_test_create_repo "$test_count" &&
 	subtree_test_create_repo "$test_count/sub proj" &&
@@ -128,6 +150,28 @@ test_expect_success 'add subproj as subtree into sub dir/ with --squash and --pr
 # Tests for 'git subtree merge'
 #
 
+test_expect_success 'merge rejects flags for split' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		test_wrong_flag git subtree merge --prefix="sub dir" --annotate=foo FETCH_HEAD &&
+		test_wrong_flag git subtree merge --prefix="sub dir" --branch=foo FETCH_HEAD &&
+		test_wrong_flag git subtree merge --prefix="sub dir" --ignore-joins FETCH_HEAD &&
+		test_wrong_flag git subtree merge --prefix="sub dir" --onto=foo FETCH_HEAD &&
+		test_wrong_flag git subtree merge --prefix="sub dir" --rejoin FETCH_HEAD
+	)
+'
+
 test_expect_success 'merge new subproj history into sub dir/ with --prefix' '
 	subtree_test_create_repo "$test_count" &&
 	subtree_test_create_repo "$test_count/sub proj" &&
@@ -262,6 +306,30 @@ test_expect_success 'split requires path given by option --prefix must exist' '
 	)
 '
 
+test_expect_success 'split rejects flags for add' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		split_hash=$(git subtree split --prefix="sub dir" --annotate="*") &&
+		test_wrong_flag git subtree split --prefix="sub dir" --squash &&
+		test_wrong_flag git subtree split --prefix="sub dir" --message=foo
+	)
+'
+
 test_expect_success 'split sub dir/ with --rejoin' '
 	subtree_test_create_repo "$test_count" &&
 	subtree_test_create_repo "$test_count/sub proj" &&
@@ -542,6 +610,26 @@ test_expect_success 'pull basic operation' '
 	)
 '
 
+test_expect_success 'pull rejects flags for split' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	(
+		test_must_fail git subtree pull --prefix="sub dir" --annotate=foo ./"sub proj" HEAD &&
+		test_must_fail git subtree pull --prefix="sub dir" --branch=foo ./"sub proj" HEAD &&
+		test_must_fail git subtree pull --prefix="sub dir" --ignore-joins ./"sub proj" HEAD &&
+		test_must_fail git subtree pull --prefix="sub dir" --onto=foo ./"sub proj" HEAD &&
+		test_must_fail git subtree pull --prefix="sub dir" --rejoin ./"sub proj" HEAD
+	)
+'
+
 #
 # Tests for 'git subtree push'
 #
@@ -584,6 +672,29 @@ test_expect_success 'push requires path given by option --prefix must exist' '
 	)
 '
 
+test_expect_success 'push rejects flags for add' '
+	subtree_test_create_repo "$test_count" &&
+	subtree_test_create_repo "$test_count/sub proj" &&
+	test_create_commit "$test_count" main1 &&
+	test_create_commit "$test_count/sub proj" sub1 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree add --prefix="sub dir" FETCH_HEAD
+	) &&
+	test_create_commit "$test_count" "sub dir"/main-sub1 &&
+	test_create_commit "$test_count" main2 &&
+	test_create_commit "$test_count/sub proj" sub2 &&
+	test_create_commit "$test_count" "sub dir"/main-sub2 &&
+	(
+		cd "$test_count" &&
+		git fetch ./"sub proj" HEAD &&
+		git subtree merge --prefix="sub dir" FETCH_HEAD &&
+		test_wrong_flag git subtree split --prefix="sub dir" --squash ./"sub proj" from-mainline &&
+		test_wrong_flag git subtree split --prefix="sub dir" --message=foo ./"sub proj" from-mainline
+	)
+'
+
 test_expect_success 'push basic operation' '
 	subtree_test_create_repo "$test_count" &&
 	subtree_test_create_repo "$test_count/sub proj" &&