From 8c0bf183745928f71fbd58f4b73afafbd6a045d4 Mon Sep 17 00:00:00 2001
From: not_compiled <dhananjayjokes@gmail.com>
Date: Mon, 17 Aug 2026 08:46:11 +0530
Subject: [PATCH] fix(spell): avoid invalid window state after async spell
 select (#41346)

Problem:
When `z=` delegates to `vim.ui.select()`, the picker may change the
current window before returning. `spell_suggest()` then continues to the
cursor restoration branch with the new window and assigns `prev_cursor`,
which belongs to the original window. This can leave Normal mode with an
invalid cursor position and produce E315.

Solution:
Clean up the spell suggestion state and return immediately after handing
control to `vim.ui.select()`.
---
 src/nvim/spellsuggest.c                |  5 +++++
 test/functional/lua/ui_select_spec.lua | 31 ++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/src/nvim/spellsuggest.c b/src/nvim/spellsuggest.c
index a87dc95592..955f558787 100644
--- a/src/nvim/spellsuggest.c
+++ b/src/nvim/spellsuggest.c
@@ -585,11 +585,16 @@ void spell_suggest(int count)
     }
   } else {
     // Hand off to (async) vim.ui.select().
+    curwin->w_p_spell = wo_spell_save;
     select_spell_suggestion(&sug);
 
     lines_left = Rows;                  // avoid more prompt
     // don't delay for 'smd' in normal_cmd()
     msg_scroll = msg_scroll_save;
+
+    spell_find_cleanup(&sug);
+    xfree(line);
+    return;
   }
 
   if (selected > 0 && selected <= sug.su_ga.ga_len && u_save_cursor() == OK) {
diff --git a/test/functional/lua/ui_select_spec.lua b/test/functional/lua/ui_select_spec.lua
index cac23aa1ed..d76f882619 100644
--- a/test/functional/lua/ui_select_spec.lua
+++ b/test/functional/lua/ui_select_spec.lua
@@ -229,6 +229,37 @@ describe('vim.ui.select()', function()
       eq(got.items[1].word, api.nvim_buf_get_lines(0, 0, -1, false)[1])
     end)
 
+    it('does not produce E315 when picker changes the current window', function()
+      prepare_test()
+
+      api.nvim_buf_set_lines(0, 0, -1, false, {
+        'Praesent enim diam,',
+        'Praesent enim diam,',
+        'Praesent enim diam,',
+        'Praesent enim diam,',
+        'Praesent enim diam,',
+      })
+      -- Keep the cursor beyond the popup's single line to reproduce E315.
+      api.nvim_win_set_cursor(0, { 5, 0 })
+
+      exec_lua(function()
+        vim.ui.select = function()
+          local buf = vim.api.nvim_create_buf(false, true)
+
+          vim.api.nvim_open_win(buf, true, {
+            row = 10,
+            col = 10,
+            height = 10,
+            width = 10,
+            relative = 'editor',
+            style = 'minimal',
+          })
+        end
+
+        vim.cmd('normal! wz=')
+      end)
+    end)
+
     it('does nothing when the user cancels', function()
       prepare_test()