Let submodule command exit with error status if path does not exist

Various subcommands of the "git submodule" command exited with 0
status even though the path given by the user did not exist.

The reason behind that was that they all pipe the output of
module_list into the while loop which then does the action on the
paths specified by the commandline. Since the exit code of the
command on the upstream side of the pipe is ignored by the shell,
the status code of "ls-files --error-unmatch" nor "module_list" was
not propagated.

In case ls-files returns with an error code, we write a special
string that is not possible in non error situations, and no other
output, so that the downstream can detect the error and die with an
error code.

The error message that there is an unmatched pathspec comes through
stderr directly from ls-files. So the user still gets a hint whats going
on.

Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-submodule.sh

@@ -73,26 +73,48 @@ resolve_relative_url ()
 #
 module_list()
 {
-	git ls-files --error-unmatch --stage -- "$@" |
+	(
+		git ls-files --error-unmatch --stage -- "$@" ||
+		echo "unmatched pathspec exists"
+	) |
 	perl -e '
 	my %unmerged = ();
 	my ($null_sha1) = ("0" x 40);
+	my @out = ();
+	my $unmatched = 0;
 	while (<STDIN>) {
+		if (/^unmatched pathspec/) {
+			$unmatched = 1;
+			next;
+		}
 		chomp;
 		my ($mode, $sha1, $stage, $path) =
 			/^([0-7]+) ([0-9a-f]{40}) ([0-3])\t(.*)$/;
 		next unless $mode eq "160000";
 		if ($stage ne "0") {
 			if (!$unmerged{$path}++) {
-				print "$mode $null_sha1 U\t$path\n";
+				push @out, "$mode $null_sha1 U\t$path\n";
 			}
 			next;
 		}
-		print "$_\n";
+		push @out, "$_\n";
+	}
+	if ($unmatched) {
+		print "#unmatched\n";
+	} else {
+		print for (@out);
 	}
 	'
 }
 
+die_if_unmatched ()
+{
+	if test "$1" = "#unmatched"
+	then
+		exit 1
+	fi
+}
+
 #
 # Map submodule path to submodule name
 #
@@ -346,6 +368,7 @@ cmd_foreach()
 	module_list |
 	while read mode sha1 stage sm_path
 	do
+		die_if_unmatched "$mode"
 		if test -e "$sm_path"/.git
 		then
 			say "$(eval_gettext "Entering '\$prefix\$sm_path'")"
@@ -398,6 +421,7 @@ cmd_init()
 	module_list "$@" |
 	while read mode sha1 stage sm_path
 	do
+		die_if_unmatched "$mode"
 		name=$(module_name "$sm_path") || exit
 
 		# Copy url setting when it is not set yet
@@ -498,6 +522,7 @@ cmd_update()
 	err=
 	while read mode sha1 stage sm_path
 	do
+		die_if_unmatched "$mode"
 		if test "$stage" = U
 		then
 			echo >&2 "Skipping unmerged submodule $sm_path"
@@ -893,6 +918,7 @@ cmd_status()
 	module_list "$@" |
 	while read mode sha1 stage sm_path
 	do
+		die_if_unmatched "$mode"
 		name=$(module_name "$sm_path") || exit
 		url=$(git config submodule."$name".url)
 		displaypath="$prefix$sm_path"
@@ -961,6 +987,7 @@ cmd_sync()
 	module_list "$@" |
 	while read mode sha1 stage sm_path
 	do
+		die_if_unmatched "$mode"
 		name=$(module_name "$sm_path")
 		url=$(git config -f .gitmodules --get submodule."$name".url)
 

t/t7400-submodule-basic.sh

@@ -258,6 +258,27 @@ test_expect_success 'init should register submodule url in .git/config' '
 	test_cmp expect url
 '
 
+test_failure_with_unknown_submodule () {
+	test_must_fail git submodule $1 no-such-submodule 2>output.err &&
+	grep "^error: .*no-such-submodule" output.err
+}
+
+test_expect_success 'init should fail with unknown submodule' '
+	test_failure_with_unknown_submodule init
+'
+
+test_expect_success 'update should fail with unknown submodule' '
+	test_failure_with_unknown_submodule update
+'
+
+test_expect_success 'status should fail with unknown submodule' '
+	test_failure_with_unknown_submodule status
+'
+
+test_expect_success 'sync should fail with unknown submodule' '
+	test_failure_with_unknown_submodule sync
+'
+
 test_expect_success 'update should fail when path is used by a file' '
 	echo hello >expect &&
 
@@ -418,10 +439,7 @@ test_expect_success 'moving to a commit without submodule does not leave empty d
 '
 
 test_expect_success 'submodule <invalid-path> warns' '
-
+	test_failure_with_unknown_submodule
-	git submodule no-such-submodule 2> output.err &&
-	grep "^error: .*no-such-submodule" output.err
-
 '
 
 test_expect_success 'add submodules without specifying an explicit path' '