1 files changed, 38 insertions, 0 deletions
diff --git a/scripts/git-submodule.sh b/scripts/git-submodule.sh
new file mode 100755
index 0000000000..d8fbc7e47e
--- /dev/null
+++ b/scripts/git-submodule.sh
@@ -0,0 +1,38 @@
+#!/bin/sh
+#
+# This code is licensed under the GPL version 2 or later.  See
+# the COPYING file in the top-level directory.
+
+set -e
+
+substat=".git-submodule-status"
+
+command=$1
+shift
+modules="$@"
+
+if test -z "$modules"
+then
+    test -e $substat || touch $substat
+    exit 0
+fi
+
+if ! test -e ".git"
+then
+    echo "$0: unexpectedly called with submodules but no git checkout exists"
+    exit 1
+fi
+
+case "$command" in
+status)
+    test -f "$substat" || exit 1
+    trap "rm -f ${substat}.tmp" EXIT
+    git submodule status $modules > "${substat}.tmp"
+    diff "${substat}" "${substat}.tmp" >/dev/null
+    exit $?
+    ;;
+update)
+    git submodule update --init $modules 1>/dev/null 2>&1
+    git submodule status $modules > "${substat}"
+    ;;
+esac