--- /dev/null
+# -*- perl -*-
+use strict;
+use warnings;
+use tests::tests;
+check_expected (IGNORE_EXIT_CODES => 1, [<<'EOF']);
+(dir-under-file) begin
+(dir-under-file) create "abc"
+(dir-under-file) mkdir "abc" (must return false)
+(dir-under-file) end
+EOF