Make Enumerable#each_cons return object if over size

This behavior changed in dfb47bbd17c3c2b8ce17dbafaf62df023b0224b2,
but only for normal exit, not for early exit.  Fix it for early
exit as well.

While here, fix example code in documentation so that it doesn't
indicate that the method returns nil.

2 files changed, 7 insertions, 5 deletions

diff --git a/enum.c b/enum.c
index a51b90296b..f8e327ff7f 100644
--- a/enum.c
+++ b/enum.c
@@ -2968,12 +2968,12 @@ enum_each_slice_size(VALUE obj, VALUE args, VALUE eobj)
  *  returns +self+:
  *
  *    a = []
- *    (1..10).each_slice(3) {|tuple| a.push(tuple) } # => nil
+ *    (1..10).each_slice(3) {|tuple| a.push(tuple) }
  *    a # => [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10]]
  *
  *    a = []
  *    h = {foo: 0, bar: 1, baz: 2, bat: 3, bam: 4}
- *    h.each_slice(2) {|tuple| a.push(tuple) } # => nil
+ *    h.each_slice(2) {|tuple| a.push(tuple) }
  *    a # => [[[:foo, 0], [:bar, 1]], [[:baz, 2], [:bat, 3]], [[:bam, 4]]]
  *
  *  With no block given, returns an Enumerator.
@@ -3047,12 +3047,12 @@ enum_each_cons_size(VALUE obj, VALUE args, VALUE eobj)
  *  returns +self+:
  *
  *    a = []
- *    (1..5).each_cons(3) {|element| a.push(element) } # => nil
+ *    (1..5).each_cons(3) {|element| a.push(element) }
  *    a # => [[1, 2, 3], [2, 3, 4], [3, 4, 5]]
  *
  *    a = []
  *    h = {foo: 0,  bar: 1, baz: 2, bam: 3}
- *    h.each_cons(2) {|element| a.push(element) } # => nil
+ *    h.each_cons(2) {|element| a.push(element) }
  *    a # => [[[:foo, 0], [:bar, 1]], [[:bar, 1], [:baz, 2]], [[:baz, 2], [:bam, 3]]]
  *
  *  With no block given, returns an Enumerator.
@@ -3068,7 +3068,7 @@ enum_each_cons(VALUE obj, VALUE n)
     if (size <= 0) rb_raise(rb_eArgError, "invalid size");
     RETURN_SIZED_ENUMERATOR(obj, 1, &n, enum_each_cons_size);
     arity = rb_block_arity();
-    if (enum_size_over_p(obj, size)) return Qnil;
+    if (enum_size_over_p(obj, size)) return obj;
     memo = MEMO_NEW(rb_ary_new2(size), dont_recycle_block_arg(arity), size);
     rb_block_call(obj, id_each, 0, 0, each_cons_i, (VALUE)memo);
 
diff --git a/test/ruby/test_enum.rb b/test/ruby/test_enum.rb
index b71ed54653..f6375a4ffc 100644
--- a/test/ruby/test_enum.rb
+++ b/test/ruby/test_enum.rb
@@ -739,6 +739,7 @@ class TestEnumerable < Test::Unit::TestCase
     assert_equal([[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]], ary)
 
     assert_equal(1..10, (1..10).each_slice(3) { })
+    assert_equal([], [].each_slice(3) { })
   end
 
   def test_each_cons
@@ -760,6 +761,7 @@ class TestEnumerable < Test::Unit::TestCase
     assert_empty(ary)
 
     assert_equal(1..5, (1..5).each_cons(3) { })
+    assert_equal([], [].each_cons(3) { })
   end
 
   def test_zip