Merge branch 'v3.3.0-rc' of https://github.com/tidyverse/ggplot2 into v3.3.0-rc

Author: thomasp85

R/guides-axis.r

@@ -193,10 +193,18 @@ draw_axis <- function(break_positions, break_labels, axis_position, theme,
   # override label element parameters for rotation
   if (inherits(label_element, "element_text")) {
     label_overrides <- axis_label_element_overrides(axis_position, angle)
-    # label_overrides is always an element_text(), but in order for the merge to
-    # keep the new class, the override must also have the new class
-    class(label_overrides) <- class(label_element)
-    label_element <- merge_element(label_overrides, label_element)
+    # label_overrides is an element_text, but label_element may not be;
+    # to merge the two elements, we just copy angle, hjust, and vjust
+    # unless their values are NULL
+    if (!is.null(label_overrides$angle)) {
+      label_element$angle <- label_overrides$angle
+    }
+    if (!is.null(label_overrides$hjust)) {
+      label_element$hjust <- label_overrides$hjust
+    }
+    if (!is.null(label_overrides$vjust)) {
+      label_element$vjust <- label_overrides$vjust
+    }
   }
 
   # conditionally set parameters that depend on axis orientation