From 7ea65f9be26d17d4bcb50b85301bf5bf379e72ef Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sat, 27 Jan 2018 10:41:43 +0000
Subject: [PATCH] compile.c: try to convert in massign `for`

* compile.c (compile_for_masgn): try to convert to an Array if an
  element of massign `for` is not an Array.
  [ruby-core:84931] [Bug #14374]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62073 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 compile.c                  |  7 ++++---
 test/ruby/test_iterator.rb | 10 ++++++++++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/compile.c b/compile.c
index 0585c294c1..4365a177b4 100644
--- a/compile.c
+++ b/compile.c
@@ -5040,7 +5040,7 @@ static int
 compile_for_masgn(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, int popped)
 {
     /* massign to var in "for"
-     * args.length == 1 && Array === (tmp = args[0]) ? tmp : args
+     * (args.length == 1 && Array.try_convert(args[0])) || args
      */
     const int line = nd_line(node);
     const NODE *var = node->nd_var;
@@ -5056,8 +5056,9 @@ compile_for_masgn(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const nod
     ADD_INSN1(ret, line, putobject, INT2FIX(0));
     ADD_CALL(ret, line, idAREF, INT2FIX(1));
     ADD_INSN1(ret, line, putobject, rb_cArray);
-    ADD_INSN1(ret, line, topn, INT2FIX(1));
-    ADD_CALL(ret, line, idEqq, INT2FIX(1));
+    ADD_INSN(ret, line, swap);
+    ADD_CALL(ret, line, rb_intern("try_convert"), INT2FIX(1));
+    ADD_INSN(ret, line, dup);
     ADD_INSNL(ret, line, branchunless, not_ary);
     ADD_INSN(ret, line, swap);
     ADD_LABEL(ret, not_ary);
diff --git a/test/ruby/test_iterator.rb b/test/ruby/test_iterator.rb
index 9bfa947607..ebfb60354a 100644
--- a/test/ruby/test_iterator.rb
+++ b/test/ruby/test_iterator.rb
@@ -107,6 +107,16 @@ class TestIterator < Test::Unit::TestCase
     assert_equal([1, 2, 3, 4, 5, 6, 7], x)
   end
 
+  def test_array_for_masgn
+    a = [Struct.new(:to_ary).new([1,2])]
+    x = []
+    a.each {|i,j|x << [i,j]}
+    assert_equal([[1,2]], x)
+    x = []
+    for i,j in a; x << [i,j]; end
+    assert_equal([[1,2]], x)
+  end
+
   def test_append_method_to_built_in_class
     x = [[1,2],[3,4],[5,6]]
     assert_equal(x.iter_test1{|e|e}, x.iter_test2{|e|e})