range.c (range_last): disable optimization when each is redefined

Do not use the optimized version of Range#last when Range#each is
redefined.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66749 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 14 insertions, 1 deletions

diff --git a/range.c b/range.c
index 77b1d7b25d..4b8d14e2c9 100644
--- a/range.c
+++ b/range.c
@@ -1088,7 +1088,8 @@ range_last(int argc, VALUE *argv, VALUE range)
 
     b = RANGE_BEG(range);
     e = RANGE_END(range);
-    if (RB_INTEGER_TYPE_P(b) && RB_INTEGER_TYPE_P(e)) {
+    if (RB_INTEGER_TYPE_P(b) && RB_INTEGER_TYPE_P(e) &&
+        RB_LIKELY(rb_method_basic_definition_p(rb_cRange, idEach))) {
         return rb_int_range_last(argc, argv, range);
     }
     return rb_ary_last(argc, argv, rb_Array(range));
diff --git a/test/ruby/test_range.rb b/test/ruby/test_range.rb
index 8c3eb08aa7..65f3a8974d 100644
--- a/test/ruby/test_range.rb
+++ b/test/ruby/test_range.rb
@@ -450,6 +450,18 @@ class TestRange < Test::Unit::TestCase
     assert_raise(ArgumentError) { (0..10).last(-1) }
   end
 
+  def test_last_with_redefine_each
+    assert_in_out_err([], <<-'end;', ['true'], [])
+      class Range
+        remove_method :each
+        def each(&b)
+          [1, 2, 3, 4, 5].each(&b)
+        end
+      end
+      puts [3, 4, 5] == (1..10).last(3)
+    end;
+  end
+
   def test_to_s
     assert_equal("0..1", (0..1).to_s)
     assert_equal("0...1", (0...1).to_s)