range.c: consider exclusive

* range.c (range_last): exclude the last number of the exclusive range
  if the end is Numeric.  [ruby-dev:47587] [Bug #8739]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42400 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 26 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index e643a13374..89e4118351 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Aug  6 17:42:47 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* range.c (range_last): exclude the last number of the exclusive range
+	  if the end is Numeric.  [ruby-dev:47587] [Bug #8739]
+
 Tue Aug  6 17:42:21 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* win32/win32.c (rb_w32_conv_from_wchar): converted string to CP_UTF8
diff --git a/range.c b/range.c
index 8fa7dcb3ba..c805848abd 100644
--- a/range.c
+++ b/range.c
@@ -887,7 +887,15 @@ range_first(int argc, VALUE *argv, VALUE range)
 static VALUE
 range_last(int argc, VALUE *argv, VALUE range)
 {
-    if (argc == 0) return RANGE_END(range);
+    if (argc == 0) {
+	VALUE e = RANGE_END(range);
+	if (!EXCL(range)) return e; /* inclusive, the end is the last */
+	/* exclusive, the last is previous to the end */
+	if (FIXNUM_P(e) || rb_obj_is_kind_of(e, rb_cNumeric))
+	    return rb_int_pred(e);
+
+	/* fallback to Array */
+    }
     return rb_ary_last(argc, argv, rb_Array(range));
 }
 
diff --git a/test/ruby/test_range.rb b/test/ruby/test_range.rb
index e12e8fc438..c50139ef9c 100644
--- a/test/ruby/test_range.rb
+++ b/test/ruby/test_range.rb
@@ -250,6 +250,18 @@ class TestRange < Test::Unit::TestCase
   def test_first_last
     assert_equal([0, 1, 2], (0..10).first(3))
     assert_equal([8, 9, 10], (0..10).last(3))
+    assert_equal(0, (0..10).first)
+    assert_equal(10, (0..10).last)
+    assert_equal("a", ("a".."c").first)
+    assert_equal("c", ("a".."c").last)
+
+    bug8739 = '[ruby-dev:47587] [Bug #8739] from exclusive range'
+    assert_equal([0, 1, 2], (0...10).first(3), bug8739)
+    assert_equal([7, 8, 9], (0...10).last(3), bug8739)
+    assert_equal(0, (0...10).first, bug8739)
+    assert_equal(9, (0...10).last, bug8739)
+    assert_equal("a", ("a"..."c").first, bug8739)
+    assert_equal("b", ("a"..."c").last, bug8739)
   end
 
   def test_to_s