From fa99afe35eb5d8cf01d875e12b53165bf1104a60 Mon Sep 17 00:00:00 2001
From: bfredl <bjorn.linse@gmail.com>
Date: Wed, 4 Sep 2024 12:09:42 +0200
Subject: fix(multibyte): handle backspace of wide clusters in replace mode

Make utf_head_off more robust against invalid sequences
and embedded NUL chars
---
 test/functional/editor/mode_insert_spec.lua | 93 +++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)

(limited to 'test/functional/editor/mode_insert_spec.lua')

diff --git a/test/functional/editor/mode_insert_spec.lua b/test/functional/editor/mode_insert_spec.lua
index fc1e6c4ee4..87d5c46134 100644
--- a/test/functional/editor/mode_insert_spec.lua
+++ b/test/functional/editor/mode_insert_spec.lua
@@ -351,4 +351,97 @@ describe('insert-mode', function()
       eq(2, api.nvim_win_get_cursor(0)[1])
     end)
   end)
+
+  it('backspace after replacing multibyte chars', function()
+    local screen = Screen.new(30, 3)
+    screen:attach()
+    api.nvim_buf_set_lines(0, 0, -1, true, { 'test ȧ̟̜̝̅̚m̆̉̐̐̇̈ å' })
+    feed('^Rabcdefghi')
+    screen:expect([[
+      abcdefghi^                     |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+
+    feed('<bs>')
+    screen:expect([[
+      abcdefgh^å                     |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+
+    feed('<bs>')
+    screen:expect([[
+      abcdefg^ å                     |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+
+    feed('<bs>')
+    screen:expect([[
+      abcdef^m̆̉̐̐̇̈ å                     |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+
+    feed('<bs>')
+    screen:expect([[
+      abcde^ȧ̟̜̝̅̚m̆̉̐̐̇̈ å                     |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+
+    feed('<bs>')
+    screen:expect([[
+      abcd^ ȧ̟̜̝̅̚m̆̉̐̐̇̈ å                     |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+
+    feed('<esc>')
+
+    api.nvim_buf_set_lines(0, 0, -1, true, { 'wow 🧑‍🌾🏳️‍⚧️x' })
+    feed('^Rabcd')
+
+    screen:expect([[
+      abcd^🧑‍🌾🏳️‍⚧️x                     |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+
+    feed('e')
+    screen:expect([[
+      abcde^🏳️‍⚧️x                      |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+
+    feed('f')
+    screen:expect([[
+      abcdef^x                       |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+
+    feed('<bs>')
+    screen:expect([[
+      abcde^🏳️‍⚧️x                      |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+
+    feed('<bs>')
+    screen:expect([[
+      abcd^🧑‍🌾🏳️‍⚧️x                     |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+
+    feed('<bs>')
+    screen:expect([[
+      abc^ 🧑‍🌾🏳️‍⚧️x                     |
+      {1:~                             }|
+      {5:-- REPLACE --}                 |
+    ]])
+  end)
 end)
-- 
cgit