ingest plain patterns as lists in layer() (#5595)

Author: teunbrand

R/geom-.R

@@ -126,9 +126,6 @@ Geom <- ggproto("Geom",
       deprecate_soft0("3.4.0", I("Using the `size` aesthetic in this geom"), I("`linewidth` in the `default_aes` field and elsewhere"))
       default_aes$linewidth <- default_aes$size
     }
-    if (is_pattern(params$fill)) {
-      params$fill <- list(params$fill)
-    }
 
     # Fill in missing aesthetics with their defaults
     missing_aes <- setdiff(names(default_aes), names(data))

R/layer.R

@@ -124,6 +124,12 @@ layer <- function(geom = NULL, stat = NULL,
 
   all <- c(geom$parameters(TRUE), stat$parameters(TRUE), geom$aesthetics())
 
+  # Take care of plain patterns provided as aesthetic
+  pattern <- vapply(aes_params, is_pattern, logical(1))
+  if (any(pattern)) {
+    aes_params[pattern] <- lapply(aes_params[pattern], list)
+  }
+
   # Warn about extra params and aesthetics
   extra_param <- setdiff(names(params), all)
   # Take care of size->linewidth renaming in layer params