Fix cmdline confirmation bug

lua/cmp/core.lua

@@ -297,7 +297,7 @@ core.filter = async.throttle(
 ---@param callback function
 core.confirm = function(self, e, option, callback)
   if not (e and not e.confirmed) then
-    return
+    return callback()
   end
   e.confirmed = true
 
@@ -319,9 +319,17 @@ core.confirm = function(self, e, option, callback)
 
   -- Restore the state again without modify the `.` register.
   end, function(next)
-    vim.api.nvim_set_current_line(e.context.cursor_line)
-    vim.api.nvim_win_set_cursor(0, { e.context.cursor.row, e.context.cursor.col - 1 })
-    next()
+    if api.is_cmdline_mode() then
+      local ctx = context.new()
+      local keys = {}
+      table.insert(keys, keymap.backspace(ctx.cursor.character - vim.str_utfindex(ctx.cursor_line, e:get_offset() - 1)))
+      table.insert(keys, string.sub(e.context.cursor_before_line, e:get_offset()))
+      feedkeys.call(table.concat(keys, ''), 'nt', next)
+    else
+      vim.api.nvim_set_current_line(e.context.cursor_line)
+      vim.api.nvim_win_set_cursor(0, { e.context.cursor.row, e.context.cursor.col - 1 })
+      next()
+    end
 
   -- Async additionalTextEdits @see https://github.com/microsoft/vscode/blob/main/src/vs/editor/contrib/suggest/suggestController.ts#L334
   end, function(next)