merge revision(s) 199b59f065ce6f1c13b8424f35a70c513523211b: [Backport #19116]

	Fix bug in array pack with shared strings

	If string literals are long and they become shared, we need to make them
	independent before we can write to them. [Bug #19116]
	---
	 pack.c                  | 1 +
	 test/ruby/test_array.rb | 6 ++++++
	 2 files changed, 7 insertions(+)

1 files changed, 6 insertions, 0 deletions

diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index a97a9c2558..ccbe85877f 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -1294,6 +1294,12 @@ class TestArray < Test::Unit::TestCase
 =end
   end
 
+  def test_pack_with_buffer
+    n = [ 65, 66, 67 ]
+    str = "a" * 100
+    assert_equal("aaaABC", n.pack("@3ccc", buffer: str.dup), "[Bug #19116]")
+  end
+
   def test_pop
     a = @cls[ 'cat', 'dog' ]
     assert_equal('dog', a.pop)