From 51982c8139b2e0f3191434c1d72b974bcf3288c6 Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sat, 10 Jun 2017 10:26:32 +0000
Subject: enumerator.c: fix nested maps

* enumerator.c (lazy_map_proc, lazy_grep_iter_proc): marks values
  returned by blocks are not packed in the case of nested maps, so
  that the result will be same as non-lazy version.  based on the
  patch by akihikodaki (Akihiko Odaki) at [ruby-core:81638],
  without GCC extension.  [Bug#13648]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59056 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 enumerator.c                      |  4 ++++
 test/ruby/test_lazy_enumerator.rb | 18 +++++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/enumerator.c b/enumerator.c
index 9de08d7d2a..a996566b7b 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -1448,6 +1448,8 @@ lazy_init_block_i(RB_BLOCK_CALL_FUNC_ARGLIST(val, m))
 #define LAZY_MEMO_PACKED_P(memo) ((memo)->memo_flags & LAZY_MEMO_PACKED)
 #define LAZY_MEMO_SET_BREAK(memo) ((memo)->memo_flags |= LAZY_MEMO_BREAK)
 #define LAZY_MEMO_SET_VALUE(memo, value) MEMO_V2_SET(memo, value)
+#define LAZY_MEMO_SET_PACKED(memo) ((memo)->memo_flags |= LAZY_MEMO_PACKED)
+#define LAZY_MEMO_RESET_PACKED(memo) ((memo)->memo_flags &= ~LAZY_MEMO_PACKED)
 
 static VALUE
 lazy_init_yielder(VALUE val, VALUE m, int argc, VALUE *argv)
@@ -1743,6 +1745,7 @@ lazy_map_proc(VALUE proc_entry, struct MEMO *result, VALUE memos, long memo_inde
 {
     VALUE value = lazyenum_yield_values(proc_entry, result);
     LAZY_MEMO_SET_VALUE(result, value);
+    LAZY_MEMO_RESET_PACKED(result);
     return result;
 }
 
@@ -1913,6 +1916,7 @@ lazy_grep_iter_proc(VALUE proc_entry, struct MEMO *result, VALUE memos, long mem
     if (!RTEST(chain)) return 0;
     value = rb_proc_call_with_block(entry->proc, 1, &(result->memo_value), Qnil);
     LAZY_MEMO_SET_VALUE(result, value);
+    LAZY_MEMO_RESET_PACKED(result);
 
     return result;
 }
diff --git a/test/ruby/test_lazy_enumerator.rb b/test/ruby/test_lazy_enumerator.rb
index 792a95bb7e..e6888583f9 100644
--- a/test/ruby/test_lazy_enumerator.rb
+++ b/test/ruby/test_lazy_enumerator.rb
@@ -14,7 +14,14 @@ class TestLazyEnumerator < Test::Unit::TestCase
 
     def each(*args)
       @args = args
-      @enum.each {|i| @current = i; yield i}
+      @enum.each do |v|
+        @current = v
+        if v.is_a? Enumerable
+          yield *v
+        else
+          yield v
+        end
+      end
     end
   end
 
@@ -100,6 +107,15 @@ class TestLazyEnumerator < Test::Unit::TestCase
     assert_equal(1, a.current)
   end
 
+  def test_map_packed_nested
+    bug = '[ruby-core:81638] [Bug#13648]'
+
+    a = Step.new([[1, 2]])
+    expected = [[[1, 2]]]
+    assert_equal(expected, a.map {|*args| args}.map {|*args| args}.to_a)
+    assert_equal(expected, a.lazy.map {|*args| args}.map {|*args| args}.to_a, bug)
+  end
+
   def test_flat_map
     a = Step.new(1..3)
     assert_equal(2, a.flat_map {|x| [x * 2]}.first)
-- 
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