Add out of bounds Ruby std::vector and std::array access testing

Also fix swig_assert_equal to work with nil as an expected input

Examples/test-suite/ruby/cpp11_li_std_array_runme.rb

@@ -108,6 +108,13 @@ ai = ArrayInt6.new([9, 8, 7, 6, 5, 4])
 arrayInPtr(ai)
 compare_containers(ai, [90, 80, 70, 60, 50, 40])
 
+# indexing
+ai = ArrayInt6.new([9, 8, 7, 6, 5, 4])
+swig_assert_equal(ai[0], 9, binding)
+swig_assert_equal(ai[5], 4, binding)
+swig_assert_equal(ai[6], nil, binding)
+swig_assert_equal(ai[-7], nil, binding)
+
 # fill
 ai.fill(111)
 compare_containers(ai, [111, 111, 111, 111, 111, 111])

Examples/test-suite/ruby/li_std_vector_runme.rb

@@ -82,6 +82,11 @@ iv[1,3] = [6,7,8,9]
 
 iv = IntVector.new([1,2,3,4])
 
+swig_assert_equal(iv[0], 1, binding)
+swig_assert_equal(iv[3], 4, binding)
+swig_assert_equal(iv[4], nil, binding)
+swig_assert_equal(iv[-5], nil, binding)
+
 iv[-1] = 9
 iv[-4] = 6
 swig_assert_equal(iv.to_s, '6239', binding)

Examples/test-suite/ruby/swig_assert.rb

@@ -22,6 +22,8 @@ end
 # msg   - optional additional message to print
 #
 def swig_assert_equal( a, b, scope = nil, msg = nil )
+  a = 'nil' if a == nil
+  b = 'nil' if b == nil
   begin
     check = "#{a} == #{b}"
     if scope.kind_of? Binding