guide_colorsteps() missbehaving with discrete values after 3.5.0

[eliocamp]

In the previous ggplot2 version (3.4.4) guide_colorsteps() would behave reasonably for discrete values:

library(ggplot2)
levels <- pretty(range(volcano))

volcano2 <- reshape2::melt(volcano) |> 
  transform(value_discrete = cut(value, 
                                 breaks = levels,
                                 ordered_result = TRUE))


ggplot(volcano2,  aes(Var1, Var2)) +
  geom_raster(aes(fill = value_discrete)) +
  guides(fill = guide_colorsteps())

^{Created on 2024-03-20 with reprex v2.0.2}

In ggplot2 3.5.0, the guide is all wonky and in the wrong order:

library(ggplot2)
levels <- pretty(range(volcano))

volcano2 <- reshape2::melt(volcano) |> 
  transform(value_discrete = cut(value, 
                                 breaks = levels,
                                 ordered_result = TRUE))


ggplot(volcano2,  aes(Var1, Var2)) +
  geom_raster(aes(fill = value_discrete)) +
  guides(fill = guide_colorsteps())

This might be something to do with the new guide system.

[teunbrand]

Thanks for the report Elio! This was reported before in #5757 and should be fixed in the development version. We plan on releasing a hotfix for the issues caused by 3.5.0 once we have a good idea what bugs it may have caused for people.

[eliocamp]

Oh, my apologies for the duplicate issue. Thanks!