Avoid opt_aset_with optimization inside multiple assignment

Previously, since the opt_aset_with optimization was introduced,
use of the opt_aset_with optimization inside multiple assignment
would result in a segfault or incorrect instructions.

Fixes [Bug #21012]

Co-authored-by: Nobuyoshi Nakada <nobu.nakada@gmail.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/test/ruby/test_assignment.rb b/test/ruby/test_assignment.rb
index 3a8dafb7f0..3d0e773c82 100644
--- a/test/ruby/test_assignment.rb
+++ b/test/ruby/test_assignment.rb
@@ -248,6 +248,16 @@ class TestAssignment < Test::Unit::TestCase
     a,b,*c = *[*[1,2]]; assert_equal([1,2,[]], [a,b,c])
   end
 
+  def test_massign_optimized_literal_bug_21012
+    a = []
+    def a.[]=(*args)
+      push args
+    end
+    a["a", "b"], = 1
+    a["a", 10], = 2
+    assert_equal [["a", "b", 1], ["a", 10, 2]], a
+  end
+
   def test_assign_rescue
     a = raise rescue 2; assert_equal(2, a)
     a, b = raise rescue [3,4]; assert_equal([3, 4], [a, b])