1 files changed, 19 insertions, 4 deletions
diff --git a/spec/ruby/core/integer/plus_spec.rb b/spec/ruby/core/integer/plus_spec.rb
index be626c3305..d01a76ab58 100644
--- a/spec/ruby/core/integer/plus_spec.rb
+++ b/spec/ruby/core/integer/plus_spec.rb
@@ -9,7 +9,7 @@ describe "Integer#+" do
       (491 + 2).should == 493
       (90210 + 10).should == 90220
 
-      (9 + bignum_value).should == 9223372036854775817
+      (9 + bignum_value).should == 18446744073709551625
       (1001 + 5.219).should == 1006.219
     end
 
@@ -29,9 +29,9 @@ describe "Integer#+" do
     end
 
     it "returns self plus the given Integer" do
-      (@bignum + 4).should == 9223372036854775888
-      (@bignum + 4.2).should be_close(9223372036854775888.2, TOLERANCE)
-      (@bignum + bignum_value(3)).should == 18446744073709551695
+      (@bignum + 4).should == 18446744073709551696
+      (@bignum + 4.2).should be_close(18446744073709551696.2, TOLERANCE)
+      (@bignum + bignum_value(3)).should == 36893488147419103311
     end
 
     it "raises a TypeError when given a non-Integer" do
@@ -40,4 +40,19 @@ describe "Integer#+" do
       -> { @bignum + :symbol}.should raise_error(TypeError)
     end
   end
+
+  it "can be redefined" do
+    code = <<~RUBY
+      class Integer
+        alias_method :old_plus, :+
+        def +(other)
+          self - other
+        end
+      end
+      result = 1 + 2
+      Integer.alias_method :+, :old_plus
+      print result
+    RUBY
+    ruby_exe(code).should == "-1"
+  end
 end