+case $# in 1|2) ;; *) usage ;; esac
+
+# Make sure we do not have .dotest
+if mkdir .dotest
+then
+ rmdir .dotest
+else
+ echo >&2 '
+It seems that I cannot create a .dotest directory, and I wonder if you
+are in the middle of patch application or another rebase. If that is not
+the case, please rm -fr .dotest and run me again. I am stopping in case
+you still have something valuable there.'
+ exit 1
+fi