Check for range == NULL - happens if no data has been added to plot (#4682)

Author: thomasp85

NEWS.md

@@ -1,5 +1,8 @@
 # ggplot2 (development version)
 
+* Fixed a bug throwing errors when trying to render an empty plot with secondary
+  axes (@thomasp85, #4509)
+
 * Axes are now added correctly in `facet_wrap()` when `as.table = FALSE`
   (@thomasp85, #4553)
 

R/axis-secondary.R

@@ -174,6 +174,12 @@ AxisSecondary <- ggproto("AxisSecondary", NULL,
 
   mono_test = function(self, scale){
     range <- scale$range$range
+
+    # Check if plot is empty
+    if (is.null(range)) {
+      return()
+    }
+
     along_range <- seq(range[1], range[2], length.out = self$detail)
     old_range <- scale$trans$inverse(along_range)