Fix off-by-one error of argc

Fix ruby/ruby#9562

1 files changed, 10 insertions, 0 deletions

diff --git a/test/ruby/test_rubyoptions.rb b/test/ruby/test_rubyoptions.rb
index b8327d15b5..e98bd9fb17 100644
--- a/test/ruby/test_rubyoptions.rb
+++ b/test/ruby/test_rubyoptions.rb
@@ -541,6 +541,16 @@ class TestRubyOptions < Test::Unit::TestCase
                       /invalid name for global variable - -# \(NameError\)/)
   end
 
+  def test_option_missing_argument
+    assert_in_out_err(%w(-0 --enable), "", [], /missing argument for --enable/)
+    assert_in_out_err(%w(-0 --disable), "", [], /missing argument for --disable/)
+    assert_in_out_err(%w(-0 --dump), "", [], /missing argument for --dump/)
+    assert_in_out_err(%w(-0 --encoding), "", [], /missing argument for --encoding/)
+    assert_in_out_err(%w(-0 --external-encoding), "", [], /missing argument for --external-encoding/)
+    assert_in_out_err(%w(-0 --internal-encoding), "", [], /missing argument for --internal-encoding/)
+    assert_in_out_err(%w(-0 --backtrace-limit), "", [], /missing argument for --backtrace-limit/)
+  end
+
   def test_assignment_in_conditional
     Tempfile.create(["test_ruby_test_rubyoption", ".rb"]) {|t|
       t.puts "if a = 1"