[GR-15736] Fix BigDecimal#dup to return the receiver rather than a new object.

PullRequest: truffleruby/833

Author: nirvdrum

CHANGELOG.md

@@ -1,3 +1,9 @@
+# 1.0 RC 18
+
+Bug fixes:
+
+* Fixed `BigDecimal#dup` so it now just returns the receiver, per Ruby 2.5+ semantics (#1680).
+
 # 1.0 RC 17
 
 Bug fixes:

lib/truffle/bigdecimal.rb

@@ -79,6 +79,10 @@ def self.limit(limit = nil)
     end
   end
 
+  def dup
+    self
+  end
+
   # TODO (pitr 20-jun-2015): remove when lazy setup is added
   def self.name
     'BigDecimal'

spec/ruby/library/bigdecimal/dup_spec.rb

@@ -0,0 +1,23 @@
+require_relative '../../spec_helper'
+require 'bigdecimal'
+
+describe "BigDecimal#dup" do
+  before :each do
+    @obj = BigDecimal("1.2345")
+  end
+
+  ruby_version_is "" ... "2.5" do
+    it "copies the BigDecimal's value to a newly allocated object" do
+      copy = @obj.dup
+
+      copy.should_not equal(@obj)
+      copy.should == @obj
+    end
+  end
+
+  ruby_version_is "2.5" do
+    it "returns self" do
+      @obj.dup.should equal(@obj)
+    end
+  end
+end