fix(lua): on_yank error with blockwise multibyte region #20162

Prevent out of range error when calling `str_byteindex`.
Use `vim.str_byteindex(bufline, #bufline)` to cacluate utf length of `bufline`.
fix #20161

1 files changed, 13 insertions, 7 deletions

diff --git a/test/functional/lua/vim_spec.lua b/test/functional/lua/vim_spec.lua
index 47a0004183..f250a3ec93 100644
--- a/test/functional/lua/vim_spec.lua
+++ b/test/functional/lua/vim_spec.lua
@@ -2227,13 +2227,19 @@ describe('lua stdlib', function()
     eq(true, exec_lua[[return vim.g.test]])
   end)
 
-  it('vim.region', function()
-    insert(helpers.dedent( [[
-    text tααt tααt text
-    text tαxt txtα tex
-    text tαxt tαxt
-    ]]))
-    eq({5,15}, exec_lua[[ return vim.region(0,{1,5},{1,14},'v',true)[1] ]])
+  describe('vim.region', function()
+    it('charwise', function()
+      insert(helpers.dedent( [[
+      text tααt tααt text
+      text tαxt txtα tex
+      text tαxt tαxt
+      ]]))
+      eq({5,15}, exec_lua[[ return vim.region(0,{1,5},{1,14},'v',true)[1] ]])
+    end)
+    it('blockwise', function()
+      insert([[αα]])
+      eq({0,5}, exec_lua[[ return vim.region(0,{0,0},{0,4},'3',true)[0] ]])
+    end)
   end)
 
   describe('vim.on_key', function()