+USAGE='<orig blob> <our blob> <their blob> <path>'
+USAGE="$USAGE <orig mode> <our mode> <their mode>"
+LONG_USAGE="Usage: git merge-one-file $USAGE
+
+Blob ids and modes should be empty for missing files."
+
+if ! test "$#" -eq 7
+then
+ echo "$LONG_USAGE"
+ exit 1
+fi
+