From 60e4f4845a1156ec3010d6a1d4510ed61b4d1f65 Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Mon, 11 Feb 2019 12:53:07 +0100
Subject: [PATCH 1/7] Add support for holed polygons using an optional subgroup
 aesthetic

---
 R/geom-polygon.r    | 87 +++++++++++++++++++++++++++++++++++----------
 R/ggplot-global.R   |  2 ++
 man/geom_map.Rd     |  1 +
 man/geom_polygon.Rd | 22 +++++++++++-
 4 files changed, 92 insertions(+), 20 deletions(-)

diff --git a/R/geom-polygon.r b/R/geom-polygon.r
index 9e9c7525ee..55fbcbea94 100644
--- a/R/geom-polygon.r
+++ b/R/geom-polygon.r
@@ -3,7 +3,10 @@
 #' Polygons are very similar to paths (as drawn by [geom_path()])
 #' except that the start and end points are connected and the inside is
 #' coloured by `fill`. The `group` aesthetic determines which cases
-#' are connected together into a polygon.
+#' are connected together into a polygon. From R 3.6 and onwards it is possible
+#' to draw polygons with holes by providing a subgroup aesthetic that
+#' differentiate the outer ring points from those describing holes in the
+#' polygon.
 #'
 #' @eval rd_aesthetics("geom", "polygon")
 #' @seealso
@@ -52,6 +55,22 @@
 #'
 #' # And if the positions are in longitude and latitude, you can use
 #' # coord_map to produce different map projections.
+#'
+#' # As of R version 3.6 geom_polygon supports polygons with holes
+#' # Use the subgroup aesthetic to differentiate holes from the main polygon
+#'
+#' holes <- do.call(rbind, lapply(split(datapoly, datapoly$id), function(df) {
+#'   df$x <- df$x + 0.5 * (mean(df$x) - df$x)
+#'   df$y <- df$y + 0.5 * (mean(df$y) - df$y)
+#'   df
+#' }))
+#' datapoly$subid <- 1L
+#' holes$subid <- 2L
+#' datapoly <- rbind(datapoly, holes)
+#'
+#' p <- ggplot(datapoly, aes(x = x, y = y)) +
+#'   geom_polygon(aes(fill = value, group = id, subgroup = subid))
+#' p
 geom_polygon <- function(mapping = NULL, data = NULL,
                          stat = "identity", position = "identity",
                          ...,
@@ -83,30 +102,60 @@ GeomPolygon <- ggproto("GeomPolygon", Geom,
     if (n == 1) return(zeroGrob())
 
     munched <- coord_munch(coord, data, panel_params)
-    # Sort by group to make sure that colors, fill, etc. come in same order
-    munched <- munched[order(munched$group), ]
 
-    # For gpar(), there is one entry per polygon (not one entry per point).
-    # We'll pull the first value from each group, and assume all these values
-    # are the same within each group.
-    first_idx <- !duplicated(munched$group)
-    first_rows <- munched[first_idx, ]
+    if (is.null(munched$subgroup)) {
+      # Sort by group to make sure that colors, fill, etc. come in same order
+      munched <- munched[order(munched$group), ]
+
+      # For gpar(), there is one entry per polygon (not one entry per point).
+      # We'll pull the first value from each group, and assume all these values
+      # are the same within each group.
+      first_idx <- !duplicated(munched$group)
+      first_rows <- munched[first_idx, ]
 
-    ggname("geom_polygon",
-      polygonGrob(munched$x, munched$y, default.units = "native",
-        id = munched$group,
-        gp = gpar(
-          col = first_rows$colour,
-          fill = alpha(first_rows$fill, first_rows$alpha),
-          lwd = first_rows$size * .pt,
-          lty = first_rows$linetype
-        )
+      ggname("geom_polygon",
+             polygonGrob(munched$x, munched$y, default.units = "native",
+                         id = munched$group,
+                         gp = gpar(
+                           col = first_rows$colour,
+                           fill = alpha(first_rows$fill, first_rows$alpha),
+                           lwd = first_rows$size * .pt,
+                           lty = first_rows$linetype
+                         )
+             )
       )
-    )
+    } else {
+      if (!grid_has_multipath) {
+        stop("Polygons with holes are only supported in R versions from 3.6 and onwards", call. = FALSE)
+      }
+      # Sort by group to make sure that colors, fill, etc. come in same order
+      munched <- munched[order(munched$group, munched$subgroup), ]
+      id <- match(munched$subgroup, unique(munched$subgroup))
+
+      # For gpar(), there is one entry per polygon (not one entry per point).
+      # We'll pull the first value from each group, and assume all these values
+      # are the same within each group.
+      first_idx <- !duplicated(munched$group)
+      first_rows <- munched[first_idx, ]
+
+      ggname("geom_polygon",
+             pathGrob(munched$x, munched$y, default.units = "native",
+                      id = id, pathId = munched$group,
+                      rule = "evenodd",
+                      gp = gpar(
+                        col = first_rows$colour,
+                        fill = alpha(first_rows$fill, first_rows$alpha),
+                        lwd = first_rows$size * .pt,
+                        lty = first_rows$linetype
+                      )
+             )
+      )
+    }
+
   },
 
   default_aes = aes(colour = "NA", fill = "grey20", size = 0.5, linetype = 1,
-    alpha = NA),
+    alpha = NA, subgroup = NULL),
 
   handle_na = function(data, params) {
     data
diff --git a/R/ggplot-global.R b/R/ggplot-global.R
index e9b871ae6c..081fc2d89f 100644
--- a/R/ggplot-global.R
+++ b/R/ggplot-global.R
@@ -44,3 +44,5 @@ ggplot_global$all_aesthetics <- .all_aesthetics
 )
 
 ggplot_global$base_to_ggplot <- .base_to_ggplot
+
+grid_has_multipath <- TRUE #packageVersion('grid') >= "3.6"
diff --git a/man/geom_map.Rd b/man/geom_map.Rd
index 3bab7a983b..07eb885020 100644
--- a/man/geom_map.Rd
+++ b/man/geom_map.Rd
@@ -68,6 +68,7 @@ This is pure annotation, so does not affect position scales.
 \item \code{group}
 \item \code{linetype}
 \item \code{size}
+\item \code{subgroup}
 }
 Learn more about setting these aesthetics in \code{vignette("ggplot2-specs")}.
 }
diff --git a/man/geom_polygon.Rd b/man/geom_polygon.Rd
index 0d91e6aeaa..0cb13b30f6 100644
--- a/man/geom_polygon.Rd
+++ b/man/geom_polygon.Rd
@@ -57,7 +57,10 @@ the default plot specification, e.g. \code{\link[=borders]{borders()}}.}
 Polygons are very similar to paths (as drawn by \code{\link[=geom_path]{geom_path()}})
 except that the start and end points are connected and the inside is
 coloured by \code{fill}. The \code{group} aesthetic determines which cases
-are connected together into a polygon.
+are connected together into a polygon. From R 3.6 and onwards it is possible
+to draw polygons with holes by providing a subgroup aesthetic that
+differentiate the outer ring points from those describing holes in the
+polygon.
 }
 \section{Aesthetics}{
 
@@ -71,6 +74,7 @@ are connected together into a polygon.
 \item \code{group}
 \item \code{linetype}
 \item \code{size}
+\item \code{subgroup}
 }
 Learn more about setting these aesthetics in \code{vignette("ggplot2-specs")}.
 }
@@ -115,6 +119,22 @@ p + geom_line(data = stream, colour = "grey30", size = 5)
 
 # And if the positions are in longitude and latitude, you can use
 # coord_map to produce different map projections.
+
+# As of R version 3.6 geom_polygon supports polygons with holes
+# Use the subgroup aesthetic to differentiate holes from the main polygon
+
+holes <- do.call(rbind, lapply(split(datapoly, datapoly$id), function(df) {
+  df$x <- df$x + 0.5 * (mean(df$x) - df$x)
+  df$y <- df$y + 0.5 * (mean(df$y) - df$y)
+  df
+}))
+datapoly$subid <- 1L
+holes$subid <- 2L
+datapoly <- rbind(datapoly, holes)
+
+p <- ggplot(datapoly, aes(x = x, y = y)) +
+  geom_polygon(aes(fill = value, group = id, subgroup = subid))
+p
 }
 \seealso{
 \code{\link[=geom_path]{geom_path()}} for an unfilled polygon,

From 858ca8fddbfb12a0521a3de6be2336e75500a8d7 Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Mon, 11 Feb 2019 13:05:08 +0100
Subject: [PATCH 2/7] Fix temporary overwrite of support flag

---
 R/ggplot-global.R | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/R/ggplot-global.R b/R/ggplot-global.R
index 081fc2d89f..37b4915106 100644
--- a/R/ggplot-global.R
+++ b/R/ggplot-global.R
@@ -45,4 +45,4 @@ ggplot_global$all_aesthetics <- .all_aesthetics
 
 ggplot_global$base_to_ggplot <- .base_to_ggplot
 
-grid_has_multipath <- TRUE #packageVersion('grid') >= "3.6"
+grid_has_multipath <- packageVersion('grid') >= "3.6"

From 2d8b1ff639d1b3ba9b9c9e25696c0adec2dc9eb7 Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Mon, 11 Feb 2019 22:02:46 +0100
Subject: [PATCH 3/7] Small style fixes suggested by Claus

---
 R/geom-polygon.r    | 50 ++++++++++++++++++++++++---------------------
 man/geom_polygon.Rd |  4 ++--
 2 files changed, 29 insertions(+), 25 deletions(-)

diff --git a/R/geom-polygon.r b/R/geom-polygon.r
index 55fbcbea94..c8c00cef8c 100644
--- a/R/geom-polygon.r
+++ b/R/geom-polygon.r
@@ -5,7 +5,7 @@
 #' coloured by `fill`. The `group` aesthetic determines which cases
 #' are connected together into a polygon. From R 3.6 and onwards it is possible
 #' to draw polygons with holes by providing a subgroup aesthetic that
-#' differentiate the outer ring points from those describing holes in the
+#' differentiates the outer ring points from those describing holes in the
 #' polygon.
 #'
 #' @eval rd_aesthetics("geom", "polygon")
@@ -56,7 +56,7 @@
 #' # And if the positions are in longitude and latitude, you can use
 #' # coord_map to produce different map projections.
 #'
-#' # As of R version 3.6 geom_polygon supports polygons with holes
+#' # As of R version 3.6 geom_polygon() supports polygons with holes
 #' # Use the subgroup aesthetic to differentiate holes from the main polygon
 #'
 #' holes <- do.call(rbind, lapply(split(datapoly, datapoly$id), function(df) {
@@ -113,16 +113,18 @@ GeomPolygon <- ggproto("GeomPolygon", Geom,
       first_idx <- !duplicated(munched$group)
       first_rows <- munched[first_idx, ]
 
-      ggname("geom_polygon",
-             polygonGrob(munched$x, munched$y, default.units = "native",
-                         id = munched$group,
-                         gp = gpar(
-                           col = first_rows$colour,
-                           fill = alpha(first_rows$fill, first_rows$alpha),
-                           lwd = first_rows$size * .pt,
-                           lty = first_rows$linetype
-                         )
-             )
+      ggname(
+        "geom_polygon",
+        polygonGrob(
+          munched$x, munched$y, default.units = "native",
+          id = munched$group,
+          gp = gpar(
+            col = first_rows$colour,
+            fill = alpha(first_rows$fill, first_rows$alpha),
+            lwd = first_rows$size * .pt,
+            lty = first_rows$linetype
+          )
+        )
       )
     } else {
       if (!grid_has_multipath) {
@@ -138,17 +140,19 @@ GeomPolygon <- ggproto("GeomPolygon", Geom,
       first_idx <- !duplicated(munched$group)
       first_rows <- munched[first_idx, ]
 
-      ggname("geom_polygon",
-             pathGrob(munched$x, munched$y, default.units = "native",
-                      id = id, pathId = munched$group,
-                      rule = "evenodd",
-                      gp = gpar(
-                        col = first_rows$colour,
-                        fill = alpha(first_rows$fill, first_rows$alpha),
-                        lwd = first_rows$size * .pt,
-                        lty = first_rows$linetype
-                      )
-             )
+      ggname(
+        "geom_polygon",
+        pathGrob(
+          munched$x, munched$y, default.units = "native",
+          id = id, pathId = munched$group,
+          rule = "evenodd",
+          gp = gpar(
+            col = first_rows$colour,
+            fill = alpha(first_rows$fill, first_rows$alpha),
+            lwd = first_rows$size * .pt,
+            lty = first_rows$linetype
+          )
+        )
       )
     }
 
diff --git a/man/geom_polygon.Rd b/man/geom_polygon.Rd
index 0cb13b30f6..bf2affeddc 100644
--- a/man/geom_polygon.Rd
+++ b/man/geom_polygon.Rd
@@ -59,7 +59,7 @@ except that the start and end points are connected and the inside is
 coloured by \code{fill}. The \code{group} aesthetic determines which cases
 are connected together into a polygon. From R 3.6 and onwards it is possible
 to draw polygons with holes by providing a subgroup aesthetic that
-differentiate the outer ring points from those describing holes in the
+differentiates the outer ring points from those describing holes in the
 polygon.
 }
 \section{Aesthetics}{
@@ -120,7 +120,7 @@ p + geom_line(data = stream, colour = "grey30", size = 5)
 # And if the positions are in longitude and latitude, you can use
 # coord_map to produce different map projections.
 
-# As of R version 3.6 geom_polygon supports polygons with holes
+# As of R version 3.6 geom_polygon() supports polygons with holes
 # Use the subgroup aesthetic to differentiate holes from the main polygon
 
 holes <- do.call(rbind, lapply(split(datapoly, datapoly$id), function(df) {

From 1901c51cac1a7232c22131b05c5a20b48f28c545 Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Tue, 12 Feb 2019 15:07:40 +0100
Subject: [PATCH 4/7] Move grid version check inside draw_panel

---
 R/geom-polygon.r  | 4 ++--
 R/ggplot-global.R | 2 --
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/R/geom-polygon.r b/R/geom-polygon.r
index c8c00cef8c..dbd631d4fb 100644
--- a/R/geom-polygon.r
+++ b/R/geom-polygon.r
@@ -127,8 +127,8 @@ GeomPolygon <- ggproto("GeomPolygon", Geom,
         )
       )
     } else {
-      if (!grid_has_multipath) {
-        stop("Polygons with holes are only supported in R versions from 3.6 and onwards", call. = FALSE)
+      if (utils::packageVersion('grid') < "3.6") {
+        stop("Polygons with holes requires R 3.6 or above", call. = FALSE)
       }
       # Sort by group to make sure that colors, fill, etc. come in same order
       munched <- munched[order(munched$group, munched$subgroup), ]
diff --git a/R/ggplot-global.R b/R/ggplot-global.R
index 37b4915106..e9b871ae6c 100644
--- a/R/ggplot-global.R
+++ b/R/ggplot-global.R
@@ -44,5 +44,3 @@ ggplot_global$all_aesthetics <- .all_aesthetics
 )
 
 ggplot_global$base_to_ggplot <- .base_to_ggplot
-
-grid_has_multipath <- packageVersion('grid') >= "3.6"

From 99f0166e5de4590ef8038e5bd6c1bfd7b093db71 Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Tue, 12 Feb 2019 15:08:52 +0100
Subject: [PATCH 5/7] Add rule argument to geom_polygon

---
 R/geom-polygon.r    | 10 ++++++++--
 man/borders.Rd      |  4 ++++
 man/geom_polygon.Rd |  9 +++++++--
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/R/geom-polygon.r b/R/geom-polygon.r
index dbd631d4fb..5395952000 100644
--- a/R/geom-polygon.r
+++ b/R/geom-polygon.r
@@ -15,6 +15,10 @@
 #' @export
 #' @inheritParams layer
 #' @inheritParams geom_point
+#' @param rule Either `"evenodd"` or `"winding"`. If polygons with holes are
+#' being drawn (using the `subgroup` aesthetic) this argument defines how the
+#' hole coordinates are interpreted. See the examples in [grid::pathGrob()] for
+#' an explanation.
 #' @examples
 #' # When using geom_polygon, you will typically need two data frames:
 #' # one contains the coordinates of each polygon (positions),  and the
@@ -73,6 +77,7 @@
 #' p
 geom_polygon <- function(mapping = NULL, data = NULL,
                          stat = "identity", position = "identity",
+                         rule = "evenodd",
                          ...,
                          na.rm = FALSE,
                          show.legend = NA,
@@ -87,6 +92,7 @@ geom_polygon <- function(mapping = NULL, data = NULL,
     inherit.aes = inherit.aes,
     params = list(
       na.rm = na.rm,
+      rule = rule,
       ...
     )
   )
@@ -97,7 +103,7 @@ geom_polygon <- function(mapping = NULL, data = NULL,
 #' @usage NULL
 #' @export
 GeomPolygon <- ggproto("GeomPolygon", Geom,
-  draw_panel = function(data, panel_params, coord) {
+  draw_panel = function(data, panel_params, coord, rule = "evenodd") {
     n <- nrow(data)
     if (n == 1) return(zeroGrob())
 
@@ -145,7 +151,7 @@ GeomPolygon <- ggproto("GeomPolygon", Geom,
         pathGrob(
           munched$x, munched$y, default.units = "native",
           id = id, pathId = munched$group,
-          rule = "evenodd",
+          rule = rule,
           gp = gpar(
             col = first_rows$colour,
             fill = alpha(first_rows$fill, first_rows$alpha),
diff --git a/man/borders.Rd b/man/borders.Rd
index 07544c8cad..eff17e1e2b 100644
--- a/man/borders.Rd
+++ b/man/borders.Rd
@@ -21,6 +21,10 @@ polygons, see \code{\link[maps:map]{maps::map()}} for details.}
 
 \item{...}{Arguments passed on to \code{geom_polygon}
 \describe{
+  \item{rule}{Either \code{"evenodd"} or \code{"winding"}. If polygons with holes are
+being drawn (using the \code{subgroup} aesthetic) this argument defines how the
+hole coordinates are interpreted. See the examples in \code{\link[grid:pathGrob]{grid::pathGrob()}} for
+an explanation.}
   \item{mapping}{Set of aesthetic mappings created by \code{\link[=aes]{aes()}} or
 \code{\link[=aes_]{aes_()}}. If specified and \code{inherit.aes = TRUE} (the
 default), it is combined with the default mapping at the top level of the
diff --git a/man/geom_polygon.Rd b/man/geom_polygon.Rd
index bf2affeddc..e771ad803c 100644
--- a/man/geom_polygon.Rd
+++ b/man/geom_polygon.Rd
@@ -5,8 +5,8 @@
 \title{Polygons}
 \usage{
 geom_polygon(mapping = NULL, data = NULL, stat = "identity",
-  position = "identity", ..., na.rm = FALSE, show.legend = NA,
-  inherit.aes = TRUE)
+  position = "identity", rule = "evenodd", ..., na.rm = FALSE,
+  show.legend = NA, inherit.aes = TRUE)
 }
 \arguments{
 \item{mapping}{Set of aesthetic mappings created by \code{\link[=aes]{aes()}} or
@@ -34,6 +34,11 @@ layer, as a string.}
 \item{position}{Position adjustment, either as a string, or the result of
 a call to a position adjustment function.}
 
+\item{rule}{Either \code{"evenodd"} or \code{"winding"}. If polygons with holes are
+being drawn (using the \code{subgroup} aesthetic) this argument defines how the
+hole coordinates are interpreted. See the examples in \code{\link[grid:pathGrob]{grid::pathGrob()}} for
+an explanation.}
+
 \item{...}{Other arguments passed on to \code{\link[=layer]{layer()}}. These are
 often aesthetics, used to set an aesthetic to a fixed value, like
 \code{colour = "red"} or \code{size = 3}. They may also be parameters

From 5f6925f838b9cc1a850fc810d00fe653d8c4ee2e Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Tue, 12 Feb 2019 15:24:10 +0100
Subject: [PATCH 6/7] make last polygon example conditional on grid version

---
 R/geom-polygon.r    | 29 ++++++++++++++++-------------
 man/geom_polygon.Rd | 31 +++++++++++++++++--------------
 2 files changed, 33 insertions(+), 27 deletions(-)

diff --git a/R/geom-polygon.r b/R/geom-polygon.r
index 5395952000..f8ed81bae9 100644
--- a/R/geom-polygon.r
+++ b/R/geom-polygon.r
@@ -60,21 +60,24 @@
 #' # And if the positions are in longitude and latitude, you can use
 #' # coord_map to produce different map projections.
 #'
-#' # As of R version 3.6 geom_polygon() supports polygons with holes
-#' # Use the subgroup aesthetic to differentiate holes from the main polygon
+#' if (packageVersion("grid") >= "3.6") {
+#'   # As of R version 3.6 geom_polygon() supports polygons with holes
+#'   # Use the subgroup aesthetic to differentiate holes from the main polygon
 #'
-#' holes <- do.call(rbind, lapply(split(datapoly, datapoly$id), function(df) {
-#'   df$x <- df$x + 0.5 * (mean(df$x) - df$x)
-#'   df$y <- df$y + 0.5 * (mean(df$y) - df$y)
-#'   df
-#' }))
-#' datapoly$subid <- 1L
-#' holes$subid <- 2L
-#' datapoly <- rbind(datapoly, holes)
+#'   holes <- do.call(rbind, lapply(split(datapoly, datapoly$id), function(df) {
+#'     df$x <- df$x + 0.5 * (mean(df$x) - df$x)
+#'     df$y <- df$y + 0.5 * (mean(df$y) - df$y)
+#'     df
+#'   }))
+#'   datapoly$subid <- 1L
+#'   holes$subid <- 2L
+#'   datapoly <- rbind(datapoly, holes)
+#'
+#'   p <- ggplot(datapoly, aes(x = x, y = y)) +
+#'     geom_polygon(aes(fill = value, group = id, subgroup = subid))
+#'   p
+#' }
 #'
-#' p <- ggplot(datapoly, aes(x = x, y = y)) +
-#'   geom_polygon(aes(fill = value, group = id, subgroup = subid))
-#' p
 geom_polygon <- function(mapping = NULL, data = NULL,
                          stat = "identity", position = "identity",
                          rule = "evenodd",
diff --git a/man/geom_polygon.Rd b/man/geom_polygon.Rd
index e771ad803c..cdf7b7a527 100644
--- a/man/geom_polygon.Rd
+++ b/man/geom_polygon.Rd
@@ -125,21 +125,24 @@ p + geom_line(data = stream, colour = "grey30", size = 5)
 # And if the positions are in longitude and latitude, you can use
 # coord_map to produce different map projections.
 
-# As of R version 3.6 geom_polygon() supports polygons with holes
-# Use the subgroup aesthetic to differentiate holes from the main polygon
-
-holes <- do.call(rbind, lapply(split(datapoly, datapoly$id), function(df) {
-  df$x <- df$x + 0.5 * (mean(df$x) - df$x)
-  df$y <- df$y + 0.5 * (mean(df$y) - df$y)
-  df
-}))
-datapoly$subid <- 1L
-holes$subid <- 2L
-datapoly <- rbind(datapoly, holes)
+if (packageVersion("grid") >= "3.6") {
+  # As of R version 3.6 geom_polygon() supports polygons with holes
+  # Use the subgroup aesthetic to differentiate holes from the main polygon
+
+  holes <- do.call(rbind, lapply(split(datapoly, datapoly$id), function(df) {
+    df$x <- df$x + 0.5 * (mean(df$x) - df$x)
+    df$y <- df$y + 0.5 * (mean(df$y) - df$y)
+    df
+  }))
+  datapoly$subid <- 1L
+  holes$subid <- 2L
+  datapoly <- rbind(datapoly, holes)
+
+  p <- ggplot(datapoly, aes(x = x, y = y)) +
+    geom_polygon(aes(fill = value, group = id, subgroup = subid))
+  p
+}
 
-p <- ggplot(datapoly, aes(x = x, y = y)) +
-  geom_polygon(aes(fill = value, group = id, subgroup = subid))
-p
 }
 \seealso{
 \code{\link[=geom_path]{geom_path()}} for an unfilled polygon,

From 5cdc09a66644379ceec5648c21b7ac9c4cb241fd Mon Sep 17 00:00:00 2001
From: Thomas Lin Pedersen <thomasp85@gmail.com>
Date: Tue, 12 Feb 2019 19:39:34 +0100
Subject: [PATCH 7/7] Add news bullet

---
 NEWS.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/NEWS.md b/NEWS.md
index 23a49eedf3..d94a40d433 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -49,6 +49,9 @@
 
 * `stat_bin()` now handles data with only one unique value (@yutannihilation #3047).
 
+* `geom_polygon()` can now draw polygons with holes using the new `subgroup` 
+  aesthetic. This functionality requires R 3.6 (@thomasp85, #3128)
+
 # ggplot2 3.1.0
 
 ## Breaking changes