Binned guides discard out-of-bound breaks (#5873)

* oob breaks are discarded

* add test

* add news bullet

Author: teunbrand

NEWS.md

@@ -1,5 +1,7 @@
 # ggplot2 (development version)
 
+* Fixed bug where binned guides would keep out-of-bounds breaks 
+  (@teunbrand, #5870).
 * The size of the `draw_key_polygon()` glyph now reflects the `linewidth` 
   aesthetic (#4852).
 * New function `complete_theme()` to replicate how themes are handled during

R/guide-bins.R

@@ -339,6 +339,7 @@ parse_binned_breaks = function(scale, breaks = scale$get_breaks()) {
     if (!is.numeric(scale$breaks)) {
       breaks <- breaks[!breaks %in% limits]
     }
+    breaks <- oob_discard(breaks, limits)
     all_breaks <- unique0(c(limits[1], breaks, limits[2]))
     bin_at <- all_breaks[-1] - diff(all_breaks) / 2
   } else {

tests/testthat/test-guides.R

@@ -300,6 +300,14 @@ test_that("guide_coloursteps and guide_bins return ordered breaks", {
   g <- guide_bins()
   key <- g$train(scale = scale, aesthetics = "colour")$key
   expect_true(all(diff(key$.value) > 0))
+
+  # Out of bound breaks are removed
+  scale <- scale_colour_viridis_c(breaks = c(10, 20, 30, 40, 50), na.value = "grey50")
+  scale$train(c(15, 45))
+
+  g <- guide_colorsteps()
+  key <- g$train(scale = scale, aesthetic = "colour")$key
+  expect_equal(sum(key$colour == "grey50"), 0)
 })
 
 test_that("guide_coloursteps can parse (un)even steps from discrete scales", {