merge revision(s) 2c8f2871a8aeff592369a993b1d69557160cfa61: [Backport #19532]

	Fix handling of 6-byte codepoints in left_adjust_char_head in CESU-8
	 encoding

	---
	 enc/cesu_8.c                | 23 +++++++++++++++++++----
	 test/ruby/enc/test_cesu8.rb |  4 ++++
	 2 files changed, 23 insertions(+), 4 deletions(-)

1 files changed, 4 insertions, 0 deletions

diff --git a/test/ruby/enc/test_cesu8.rb b/test/ruby/enc/test_cesu8.rb
index d9debe76cd..68a08389ea 100644
--- a/test/ruby/enc/test_cesu8.rb
+++ b/test/ruby/enc/test_cesu8.rb
@@ -106,4 +106,8 @@ EOT
       assert_equal chr, ord.chr("cesu-8")
     end
   end
+
+  def test_cesu8_left_adjust_char_head
+    assert_equal("", "\u{10000}".encode("cesu-8").chop)
+  end
 end