Cannot have more than one shape after subplot()

I guess this is related to #1333

Here is the issue: it doesn't seem possible to have more than one shape after subplot() is called. Applying the shapes to the individual plots work, though.

reprex that works:

library(plotly)

p1 <- plot_ly(mtcars, x = ~mpg, y = ~hp) %>% 
  layout(
    shapes = list(
      list(
        type = "line", 
        line = list(color = "#5681c4", dash = "dot"),
        x0 = 20, 
        x1 = 20,
        y0 = 0,
        y1 = 1,
        yref = "paper"
      ),
      list(
        type = "line", 
        line = list(color = "#5681c4", dash = "solid"),
        x0 = 30, 
        x1 = 30,
        y0 = 0,
        y1 = 1,
        yref = "paper"
      )
    )
  ) %>%
  config(editable = TRUE)

p2 <- plot_ly(mtcars, x = ~mpg, y = ~drat) %>% 
  layout(
    shapes = list(
      list(
        type = "line", 
        line = list(color = "#5681c4", dash = "dot"),
        x0 = 20, 
        x1 = 20,
        y0 = 0,
        y1 = 1,
        yref = "paper"
      ),
      list(
        type = "line", 
        line = list(color = "#5681c4", dash = "solid"),
        x0 = 30, 
        x1 = 30,
        y0 = 0,
        y1 = 1,
        yref = "paper"
      )
    )
  ) %>%
  config(editable = TRUE)

subplot(p1, p2, nrows = 2)

reprex that does not work:

library(plotly)

p1 <- plot_ly(mtcars, x = ~mpg, y = ~hp)

p2 <- plot_ly(mtcars, x = ~mpg, y = ~drat)

subplot(p1, p2, nrows = 2) %>% 
  layout(
    shapes = list(
      list(
        type = "line", 
        line = list(color = "#5681c4", dash = "dot"),
        x0 = 20, 
        x1 = 20,
        y0 = 0,
        y1 = 1,
        yref = "paper"
      ),
      list(
        type = "line", 
        line = list(color = "#5681c4", dash = "solid"),
        x0 = 30, 
        x1 = 30,
        y0 = 0,
        y1 = 1,
        yref = "paper"
      )
    )
  ) %>%
  config(editable = TRUE)

reprex with only one shape - it works:

library(plotly)

p1 <- plot_ly(mtcars, x = ~mpg, y = ~hp)

p2 <- plot_ly(mtcars, x = ~mpg, y = ~drat)

subplot(p1, p2, nrows = 2) %>% 
  layout(
    shapes = list(
      type = "line", 
      line = list(color = "#5681c4", dash = "dot"),
      x0 = 20, 
      x1 = 20,
      y0 = 0,
      y1 = 1,
      yref = "paper"
    )
  ) %>%
  config(editable = TRUE)

Any thoughts?

首先运行 issue 中正常工作的和失败的 reprex，比较提供给每个 plot 的 shapes 与在 subplot() 之后添加的 shapes。跟踪 subplot() 如何组合这些 plot，以及后续的 layout(shapes = ...) 调用如何被处理。完成的标准是两个 shapes 都能在 subplot 中渲染，并且仍可通过 config(editable = TRUE) 编辑。