vim-patch:8.1.1071: cannot get composing characters from the screen

Problem:    Cannot get composing characters from the screen.
Solution:   Add screenchars() and screenstring(). (partly by Ozaki Kiichi,
            closes vim/vim#4059)
https://github.com/vim/vim/commit/2912abb3a2fd72074e3901c8ae1d4a77ce764675

1 files changed, 35 insertions, 0 deletions

diff --git a/src/nvim/testdir/test_utf8.vim b/src/nvim/testdir/test_utf8.vim
index c51fb3a759..acf15e0e28 100644
--- a/src/nvim/testdir/test_utf8.vim
+++ b/src/nvim/testdir/test_utf8.vim
@@ -1,5 +1,6 @@
 " Tests for Unicode manipulations
  
+source view_util.vim
 
 " Visual block Insert adjusts for multi-byte char
 func Test_visual_block_insert()
@@ -61,6 +62,40 @@ func Test_getvcol()
   call assert_equal(2, virtcol("']"))
 endfunc
 
+func Test_screenchar_utf8()
+  new
+
+  " 1-cell, with composing characters 
+  call setline(1, ["ABC\u0308"])
+  redraw
+  call assert_equal([0x0041], screenchars(1, 1))
+  call assert_equal([0x0042], screenchars(1, 2))
+  call assert_equal([0x0043, 0x0308], screenchars(1, 3))
+  call assert_equal("A", screenstring(1, 1))
+  call assert_equal("B", screenstring(1, 2))
+  call assert_equal("C\u0308", screenstring(1, 3))
+
+  " 2-cells, with composing characters 
+  let text = "\u3042\u3044\u3046\u3099"
+  call setline(1, text)
+  redraw
+  call assert_equal([0x3042], screenchars(1, 1))
+  call assert_equal([0], screenchars(1, 2))
+  call assert_equal([0x3044], screenchars(1, 3))
+  call assert_equal([0], screenchars(1, 4))
+  call assert_equal([0x3046, 0x3099], screenchars(1, 5))
+
+  call assert_equal("\u3042", screenstring(1, 1))
+  call assert_equal("", screenstring(1, 2))
+  call assert_equal("\u3044", screenstring(1, 3))
+  call assert_equal("", screenstring(1, 4))
+  call assert_equal("\u3046\u3099", screenstring(1, 5))
+
+  call assert_equal([text . '  '], ScreenLinesUtf8(1, 8))
+
+  bwipe!
+endfunc
+
 func Test_list2str_str2list_utf8()
   " One Unicode codepoint
   let s = "\u3042\u3044"