Fix #2466: scale_*_manual with unused aesthetics no longer errors

When a scale has aesthetics = c("colour", "fill") but the plot only uses
"colour", the code would try to access the non-existent "fill" column
and error with "undefined columns selected".

The fix uses intersect() to only process aesthetics that actually exist
in each layer's data.

Note: Trace splitting with multi-aesthetic scales is a separate issue (#2467).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: cpsievert

R/ggplotly.R

@@ -411,9 +411,10 @@ gg2list <- function(p, width = NULL, height = NULL,
       # of each non-positional scale for display in tooltips
       for (sc in npscales$scales) {
         data <- lapply(data, function(d) {
-          # scale may not be relevant for every layer data
-          if (any(names(d) %in% sc$aesthetics)) {
-            d[paste0(sc$aesthetics, "_plotlyDomain")] <- d[sc$aesthetics]
+          # Only process aesthetics that actually exist in this layer's data
+          present_aes <- intersect(sc$aesthetics, names(d))
+          if (length(present_aes) > 0) {
+            d[paste0(present_aes, "_plotlyDomain")] <- d[present_aes]
           }
           d
         })

tests/testthat/test-ggplot-color.R

@@ -1,10 +1,23 @@
 df = data.frame(width = 1:3, height = 1:3, col = letters[1:3])
 test_that("ggplotly automatically converts `color` aes to `colour`", {
-    p <- qplot(width, height, 
+    p <- qplot(width, height,
                         data = df, color = col)
     # color variable is not shown
     color <- plotly_build(ggplotly(p, tooltip = c("color")))
     # colour (with u!) variable is shown
     expect_identical(color$x$data, plotly_build(ggplotly(p, tooltip = c("colour")))$x$data)
 })
 
+test_that("scale_*_manual with unused aesthetics does not error (#2466)", {
+  # scale has aesthetics = c('colour', 'fill') but plot only uses 'colour'
+  p <- ggplot(iris, aes(Sepal.Length, Sepal.Width, colour = Species)) +
+    geom_point() +
+    scale_colour_manual(
+      values = c("setosa" = "red", "versicolor" = "blue", "virginica" = "green"),
+      aesthetics = c("colour", "fill")
+    )
+  # Should not error with "undefined columns selected"
+  # (Note: trace splitting with multi-aesthetic scales is a separate issue #2467)
+  expect_error(plotly_build(ggplotly(p)), NA)
+})
+