patch 9.1.1156: tests: No test for what patch 9.1.1152 fixes

Problem:  No test for what patch 9.1.1152 fixes.
Solution: Add a test (zeertzjq).

closes: #16742

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

Author: zeertzjq

src/testdir/test_registers.vim

@@ -264,6 +264,20 @@ func Test_zz_recording_with_select_mode_utf8_gui()
   call Run_test_recording_with_select_mode_utf8()
 endfunc
 
+func Test_recording_append_utf8()
+  new
+
+  let keys = "cc哦洛固四最倒倀\<Esc>0"
+  call feedkeys($'qr{keys}q', 'xt')
+  call assert_equal(keys, @r)
+
+  let morekeys = "A…foobar\<Esc>0"
+  call feedkeys($'qR{morekeys}q', 'xt')
+  call assert_equal(keys .. morekeys, @r)
+
+  bwipe!
+endfunc
+
 func Test_recording_with_super_mod()
   if "\<D-j>"[-1:] == '>'
     throw 'Skipped: <D- modifier not supported'

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1156,
 /**/
     1155,
 /**/