add script for reporting duplicate commits

diff --git a/dup_commit b/dup_commit
new file mode 100755 (executable)
index 0000000..75627b6
--- /dev/null
+++ b/dup_commit
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+subject="duplicate patches in the BRANCH tree"
+
+tools_dir=$(dirname "$0")
+"$tools_dir"/message_helper "$@" "$subject" <<EOF
+The following commits are also in Linus Torvalds' tree as different commits
+(but the same patches):
+
+EOF
+
+exit 0