Add applypatch-msg hook for Signed-off-by line checking

scripts/hooks/applypatch-msg.check-signed-off.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+#
+# An hook script to check the commit log message taken by
+# applypatch from an e-mail message for proper "Signed-off-by" line(s).
+#
+# To enable this hook, copy this file to ".git/hooks/applypatch-msg" and make it
+# executable.
+
+#
+# This hook is used when applying patches which are send via mail, to verify the
+# Signed-off-by line is in the commit message.
+#
+
+. git-sh-setup
+
+RED='\e[0;31m'      # Red
+YELLOW='\e[0;33m'   # Yellow
+NORMAL='\e[0m'      # Text Reset
+
+warn() {
+    echo -e >&2 "${YELLOW}$*${DEFAULT}"
+}
+
+abort() {
+    echo -e >&2 "${RED}$*${DEFAULT}"
+    exit 1
+}
+
+headline=$(head -n 1 $1 | wc -c)
+[[ $headline -gt 50 ]] && warn "Headline of patch longer than 50 chars"
+
+grep "^Signed-off-by" $1 >/dev/null 2>/dev/null && abort "No Signed-off-by line"
+