Subplot with faceted ggplots: misplaced facet strips with nrows>1

When passing faceted ggplots to subplot(), the result is rendered properly as long as nrows=1. However, once I pass nrows=2 or greater, the facet strips become misplaced.

require(ggplot)
require(plotly)

ggiris <- qplot(Petal.Width, Sepal.Length, data = iris, color = Species)
# With nrows = 1, facets are rendered properly
subplot (ggiris , ggiris+facet_wrap(~Species))
# With nrows>1, facets are messed up
subplot (ggiris , ggiris+facet_wrap(~Species), nrows=2)

This used to work correctly on my system, using a previous version of the library - I found the error after updating plotly and a bunch of other libraries. Unfortunately, I haven't been able to restore the previous environment, so I don't know on which release it stopped working.

首先使用 subplot()、facet_wrap() 和 nrows=2 重现 issue 中的示例，然后跟踪 subplot 的入口点，以及它对分面 ggplots 和行布局的处理。完成标准是：当 nrows 大于 1 时，分面条带仍能保持正确定位，并且有一个覆盖所报告示例的回归测试。