通常，图例中项目的顺序可通过使用因子并确保级别按所需顺序进行控制。例如，在下面的代码中，此操作完全按预期方式工作，但在最后一个图中除外，在该图中图例的顺序不正确（例如，它从期望的顺序-1.1，-0.9，0切换到字母顺序，而不是期望的顺序-0.9，-1.1，0）。有哪些方法可以解决这个问题？另外，它是一个bug吗？

library(dplyr)
library(ggplot2)

Z <- tibble(x = c(-1.11, -0.9,  0), x_fct = factor(x)) # Note: factor levels are in correct (i.e., numerical) order

Z |> # Legend in correct order (but no 'circle filled' yet)
  ggplot(aes(x, x, color = x_fct)) +
  geom_point() 

Z |> # Legend is in correct order but `geom_poin()` is obscured by 'circle filled'
  ggplot(aes(x, x, color = x_fct)) +
  geom_point() +
  geom_point(shape = 'circle filled', size = 10, fill='grey', data = ~ . |> filter(x > min(x)))

Z |> # Legend in correct order
  ggplot(aes(x, x, color = x_fct)) +
  geom_point(shape = 'circle filled', size = 10, fill='grey', data = ~ . |> filter(TRUE)) + # `data=...` just to mirror above
  geom_point() 

Z |> # Legend in INCORRECT order
  ggplot(aes(x, x, color = x_fct)) +
  geom_point(shape = 'circle filled', size = 10, fill='grey', data = ~ . |> filter(x > min(x))) +
  geom_point()