fix(diagnostics): fixed virtual_text cursormoved autocmd error (#34017)

runtime/lua/vim/diagnostic.lua

@@ -1609,21 +1609,33 @@ M.handlers.underline = {
 --- @param opts vim.diagnostic.Opts.VirtualText
 local function render_virtual_text(namespace, bufnr, diagnostics, opts)
   local lnum = api.nvim_win_get_cursor(0)[1] - 1
+  local buf_len = api.nvim_buf_line_count(bufnr)
   api.nvim_buf_clear_namespace(bufnr, namespace, 0, -1)
 
-  for line, line_diagnostics in pairs(diagnostics) do
-    local virt_texts = M._get_virt_text_chunks(line_diagnostics, opts)
-    local skip = (opts.current_line == true and line ~= lnum)
+  local function should_render(line)
+    if
+      (line >= buf_len)
+      or (opts.current_line == true and line ~= lnum)
       or (opts.current_line == false and line == lnum)
+    then
+      return false
+    end
 
-    if virt_texts and not skip then
-      api.nvim_buf_set_extmark(bufnr, namespace, line, 0, {
-        hl_mode = opts.hl_mode or 'combine',
-        virt_text = virt_texts,
-        virt_text_pos = opts.virt_text_pos,
-        virt_text_hide = opts.virt_text_hide,
-        virt_text_win_col = opts.virt_text_win_col,
-      })
+    return true
+  end
+
+  for line, line_diagnostics in pairs(diagnostics) do
+    if should_render(line) then
+      local virt_texts = M._get_virt_text_chunks(line_diagnostics, opts)
+      if virt_texts then
+        api.nvim_buf_set_extmark(bufnr, namespace, line, 0, {
+          hl_mode = opts.hl_mode or 'combine',
+          virt_text = virt_texts,
+          virt_text_pos = opts.virt_text_pos,
+          virt_text_hide = opts.virt_text_hide,
+          virt_text_win_col = opts.virt_text_win_col,
+        })
+      end
     end
   end
 end

test/functional/lua/diagnostic_spec.lua

@@ -2204,6 +2204,31 @@ describe('vim.diagnostic', function()
       eq(1, #result)
       eq(' Another error there!', result[1][4].virt_text[3][1])
     end)
+
+    it('only renders virtual_line diagnostics within buffer length', function()
+      local result = exec_lua(function()
+        vim.api.nvim_win_set_cursor(0, { 1, 0 })
+
+        vim.diagnostic.config({ virtual_text = { current_line = false } })
+
+        vim.diagnostic.set(_G.diagnostic_ns, _G.diagnostic_bufnr, {
+          _G.make_error('Hidden Error here!', 0, 0, 0, 0, 'foo_server'),
+          _G.make_error('First Error here!', 1, 0, 1, 0, 'foo_server'),
+          _G.make_error('Second Error here!', 2, 0, 2, 0, 'foo_server'),
+          _G.make_error('First Ignored Error here!', 3, 0, 3, 0, 'foo_server'),
+          _G.make_error('Second Ignored Error here!', 6, 0, 6, 0, 'foo_server'),
+          _G.make_error('Third Ignored Error here!', 8, 0, 8, 0, 'foo_server'),
+        })
+
+        vim.api.nvim_buf_set_lines(_G.diagnostic_bufnr, 2, 5, false, {})
+        vim.api.nvim_exec_autocmds('CursorMoved', { buffer = _G.diagnostic_bufnr })
+        return _G.get_virt_text_extmarks(_G.diagnostic_ns)
+      end)
+
+      eq(2, #result)
+      eq(' First Error here!', result[1][4].virt_text[3][1])
+      eq(' Second Error here!', result[2][4].virt_text[3][1])
+    end)
   end)
 
   describe('handlers.virtual_lines', function()

test/functional/ui/decorations_spec.lua

@@ -3412,7 +3412,7 @@ describe('extmark decorations', function()
         {4:^1}                                                 |
         {4:1}                                                 |*13
                                                           |
-      ]]
+      ]],
     })
     feed('<C-e>')
     -- Newly visible line should also have the highlight.
@@ -3421,7 +3421,7 @@ describe('extmark decorations', function()
         {4:^1}                                                 |
         {4:1}                                                 |*13
                                                           |
-      ]]
+      ]],
     })
   end)
 end)