fix: when not lazy render chunk, didn't check whether lnum is invalid

Author: shellRaining

docs/init.md

@@ -155,7 +155,10 @@ function ChunkMod:render(range, opts)
         for i, vt in ipairs(virt_text_list) do
             row_opts.virt_text = { { vt, text_hl } }
             row_opts.virt_text_win_col = virt_text_win_col_list[i]
-            api.nvim_buf_set_extmark(range.bufnr, self.meta.ns_id, row_list[i], 0, row_opts)
+            local row = row_list[i]
+            if api.nvim_buf_is_valid(range.bufnr) and api.nvim_buf_line_count(range.bufnr) > row then
+                api.nvim_buf_set_extmark(range.bufnr, self.meta.ns_id, row, 0, row_opts)
+            end
         end
     else
         self.meta.task = LoopTask(function(vt, row, vt_win_col)