From 6cf19b0204eee97175d6bf5066cadb79c92811b1 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <49372158+teunbrand@users.noreply.github.com>
Date: Thu, 8 Dec 2022 22:05:05 +0100
Subject: [PATCH 1/6] Use cache to track original defaults

---
 R/geom-defaults.r      | 61 +++++++++++++++++++++++++++++++++++-------
 man/update_defaults.Rd |  6 +++--
 2 files changed, 55 insertions(+), 12 deletions(-)

diff --git a/R/geom-defaults.r b/R/geom-defaults.r
index 1fefa8c66e..edbd11a617 100644
--- a/R/geom-defaults.r
+++ b/R/geom-defaults.r
@@ -1,28 +1,69 @@
+geom_defaults_cache <- new.env(parent = emptyenv())
+stat_defaults_cache <- new.env(parent = emptyenv())
+
 #' Modify geom/stat aesthetic defaults for future plots
 #'
 #' @param stat,geom Name of geom/stat to modify (like `"point"` or
 #'   `"bin"`), or a Geom/Stat object (like `GeomPoint` or
 #'   `StatBin`).
-#' @param new Named list of aesthetics.
+#' @param new Named list of aesthetics. Alternatively, `NULL` to reset the
+#'   defaults.
 #' @keywords internal
 #' @export
 #' @examples
 #' update_geom_defaults("point", list(colour = "darkblue"))
 #' ggplot(mtcars, aes(mpg, wt)) + geom_point()
-#' update_geom_defaults("point", list(colour = "black"))
+#' # Reset defaults by using `new = NULL`
+#' update_geom_defaults("point", NULL)
 #' @rdname update_defaults
 update_geom_defaults <- function(geom, new) {
-  g <- check_subclass(geom, "Geom", env = parent.frame())
-  old <- g$default_aes
-  g$default_aes <- defaults(rename_aes(new), old)
-  invisible()
+  if (is.null(new)) {
+
+    vec_assert(geom, character(), 1)
+    old <- geom_defaults_cache[[geom]]
+    if (!is.null(old)) {
+      new <- update_geom_defaults(geom, old)
+      env_unbind(geom_defaults_cache, geom)
+    }
+    invisible(new)
+
+  } else {
+
+    g <- check_subclass(geom, "Geom", env = parent.frame())
+    old <- g$default_aes
+    # Only update cache the first time
+    if (!geom %in% ls(geom_defaults_cache)) {
+      geom_defaults_cache[[geom]] <- old
+    }
+    g$default_aes <- defaults(rename_aes(new), old)
+    invisible(old)
+
+  }
 }
 
 #' @rdname update_defaults
 #' @export
 update_stat_defaults <- function(stat, new) {
-  g <- check_subclass(stat, "Stat", env = parent.frame())
-  old <- g$default_aes
-  g$default_aes <- defaults(rename_aes(new), old)
-  invisible()
+  if (is.null(new)) {
+
+    vec_assert(stat, character(), 1)
+    old <- stat_defaults_cache[[stat]]
+    if (!is.null(old)) {
+      new <- update_geom_defaults(stat, old)
+      env_unbind(geom_defaults_cache, stat)
+    }
+    invisible(new)
+
+  } else {
+
+    g <- check_subclass(stat, "Stat", env = parent.frame())
+    old <- g$default_aes
+    # Only update cache the first time
+    if (!stat %in% ls(stat_defaults_cache)) {
+      stat_defaults_cache[[stat]] <- old
+    }
+    g$default_aes <- defaults(rename_aes(new), old)
+    invisible(old)
+
+  }
 }
diff --git a/man/update_defaults.Rd b/man/update_defaults.Rd
index b3cc710eb7..b68cc05d32 100644
--- a/man/update_defaults.Rd
+++ b/man/update_defaults.Rd
@@ -10,7 +10,8 @@ update_geom_defaults(geom, new)
 update_stat_defaults(stat, new)
 }
 \arguments{
-\item{new}{Named list of aesthetics.}
+\item{new}{Named list of aesthetics. Alternatively, \code{NULL} to reset the
+defaults.}
 
 \item{stat, geom}{Name of geom/stat to modify (like \code{"point"} or
 \code{"bin"}), or a Geom/Stat object (like \code{GeomPoint} or
@@ -22,6 +23,7 @@ Modify geom/stat aesthetic defaults for future plots
 \examples{
 update_geom_defaults("point", list(colour = "darkblue"))
 ggplot(mtcars, aes(mpg, wt)) + geom_point()
-update_geom_defaults("point", list(colour = "black"))
+# Reset defaults by using `new = NULL`
+update_geom_defaults("point", NULL)
 }
 \keyword{internal}

From 3433f9aec6329587dab1ae4eaf0d8968dc9fd341 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <49372158+teunbrand@users.noreply.github.com>
Date: Thu, 8 Dec 2022 22:05:12 +0100
Subject: [PATCH 2/6] Add unit test

---
 tests/testthat/test-geom-.R | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tests/testthat/test-geom-.R b/tests/testthat/test-geom-.R
index 9436770838..c662485f40 100644
--- a/tests/testthat/test-geom-.R
+++ b/tests/testthat/test-geom-.R
@@ -5,3 +5,19 @@ test_that("aesthetic checking in geom throws correct errors", {
   aes <- list(a = 1:4, b = letters[1:4], c = TRUE, d = 1:2, e = 1:5)
   expect_snapshot_error(check_aesthetics(aes, 4))
 })
+
+test_that("geom defaults can be set and reset", {
+  l <- geom_point()
+  test <- l$geom$use_defaults(data_frame0())
+  expect_equal(test$colour, "black")
+
+  inv <- update_geom_defaults("point", list(colour = "red"))
+  test <- l$geom$use_defaults(data_frame0())
+  expect_equal(test$colour, "red")
+  expect_equal(inv$colour, "black")
+
+  inv <- update_geom_defaults("point", NULL)
+  test <- l$geom$use_defaults(data_frame0())
+  expect_equal(test$colour, "black")
+  expect_equal(inv$colour, "red")
+})

From 3c7aeb0aeecc6389f47cd3fd3516359fa31ee1ab Mon Sep 17 00:00:00 2001
From: Teun van den Brand <49372158+teunbrand@users.noreply.github.com>
Date: Thu, 8 Dec 2022 22:06:44 +0100
Subject: [PATCH 3/6] Add NEWS bullet

---
 NEWS.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/NEWS.md b/NEWS.md
index 76bf5100a3..d13b674d4e 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,7 @@
 # ggplot2 (development version)
 
+* `update_geom_defaults()` and `update_stat_defaults()` can now use `new = NULL`
+  to reset the original defaults (@teunbrand, #4993).
 * Fixed a regression in `geom_hex()` where aesthetics were replicated across 
   bins (@thomasp85, #5037 and #5044)
 * Fixed spurious warning when `weight` aesthetic was used in `stat_smooth()` 

From 6483980c1ace6217e0945d3179761d5f46370255 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <49372158+teunbrand@users.noreply.github.com>
Date: Sun, 11 Dec 2022 12:05:58 +0100
Subject: [PATCH 4/6] Rename cache

---
 R/geom-defaults.r | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/R/geom-defaults.r b/R/geom-defaults.r
index edbd11a617..17dc395245 100644
--- a/R/geom-defaults.r
+++ b/R/geom-defaults.r
@@ -1,5 +1,5 @@
-geom_defaults_cache <- new.env(parent = emptyenv())
-stat_defaults_cache <- new.env(parent = emptyenv())
+cache_geom_defaults <- new.env(parent = emptyenv())
+cache_stats_defaults <- new.env(parent = emptyenv())
 
 #' Modify geom/stat aesthetic defaults for future plots
 #'
@@ -20,10 +20,10 @@ update_geom_defaults <- function(geom, new) {
   if (is.null(new)) {
 
     vec_assert(geom, character(), 1)
-    old <- geom_defaults_cache[[geom]]
+    old <- cache_geom_defaults[[geom]]
     if (!is.null(old)) {
       new <- update_geom_defaults(geom, old)
-      env_unbind(geom_defaults_cache, geom)
+      env_unbind(cache_geom_defaults, geom)
     }
     invisible(new)
 
@@ -32,8 +32,8 @@ update_geom_defaults <- function(geom, new) {
     g <- check_subclass(geom, "Geom", env = parent.frame())
     old <- g$default_aes
     # Only update cache the first time
-    if (!geom %in% ls(geom_defaults_cache)) {
-      geom_defaults_cache[[geom]] <- old
+    if (!geom %in% ls(cache_geom_defaults)) {
+      cache_geom_defaults[[geom]] <- old
     }
     g$default_aes <- defaults(rename_aes(new), old)
     invisible(old)
@@ -47,10 +47,10 @@ update_stat_defaults <- function(stat, new) {
   if (is.null(new)) {
 
     vec_assert(stat, character(), 1)
-    old <- stat_defaults_cache[[stat]]
+    old <- cache_stats_defaults[[stat]]
     if (!is.null(old)) {
-      new <- update_geom_defaults(stat, old)
-      env_unbind(geom_defaults_cache, stat)
+      new <- update_stat_defaults(stat, old)
+      env_unbind(cache_stats_defaults, stat)
     }
     invisible(new)
 
@@ -59,8 +59,8 @@ update_stat_defaults <- function(stat, new) {
     g <- check_subclass(stat, "Stat", env = parent.frame())
     old <- g$default_aes
     # Only update cache the first time
-    if (!stat %in% ls(stat_defaults_cache)) {
-      stat_defaults_cache[[stat]] <- old
+    if (!stat %in% ls(cache_stats_defaults)) {
+      cache_stats_defaults[[stat]] <- old
     }
     g$default_aes <- defaults(rename_aes(new), old)
     invisible(old)

From a54e6f7ccc7f0384823fea00c2b6439e06043e78 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <49372158+teunbrand@users.noreply.github.com>
Date: Mon, 8 May 2023 21:01:15 +0200
Subject: [PATCH 5/6] Better checking

---
 R/geom-defaults.R | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/R/geom-defaults.R b/R/geom-defaults.R
index 7ad1775b1f..3b8d87f263 100644
--- a/R/geom-defaults.R
+++ b/R/geom-defaults.R
@@ -37,7 +37,12 @@ cache_stats_defaults <- new.env(parent = emptyenv())
 update_geom_defaults <- function(geom, new) {
   if (is.null(new)) {
 
-    vec_assert(geom, character(), 1)
+    if (!inherits(geom, "Geom")) {
+      check_string(geom)
+    } else {
+      geom <- check_subclass(geom, "Geom", env = parent.frame())
+      geom <- gsub("^geom_", "", snake_class(geom))
+    }
     old <- cache_geom_defaults[[geom]]
     if (!is.null(old)) {
       new <- update_geom_defaults(geom, old)
@@ -67,7 +72,12 @@ update_geom_defaults <- function(geom, new) {
 update_stat_defaults <- function(stat, new) {
   if (is.null(new)) {
 
-    vec_assert(stat, character(), 1)
+    if (!inherits(stat, "Stat")) {
+      check_string(stat)
+    } else {
+      stat <- check_subclass(stat, "Stat", env = parent.frame())
+      stat <- gsub("^stat_", "", snake_class(stat))
+    }
     old <- cache_stats_defaults[[stat]]
     if (!is.null(old)) {
       new <- update_stat_defaults(stat, old)

From 46a6a6ac91c0a8989b8bb1343f52cac7f8950559 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <49372158+teunbrand@users.noreply.github.com>
Date: Mon, 8 May 2023 21:01:30 +0200
Subject: [PATCH 6/6] Don't empty caches

---
 R/geom-defaults.R | 2 --
 1 file changed, 2 deletions(-)

diff --git a/R/geom-defaults.R b/R/geom-defaults.R
index 3b8d87f263..375650f8e1 100644
--- a/R/geom-defaults.R
+++ b/R/geom-defaults.R
@@ -46,7 +46,6 @@ update_geom_defaults <- function(geom, new) {
     old <- cache_geom_defaults[[geom]]
     if (!is.null(old)) {
       new <- update_geom_defaults(geom, old)
-      env_unbind(cache_geom_defaults, geom)
     }
     invisible(new)
 
@@ -81,7 +80,6 @@ update_stat_defaults <- function(stat, new) {
     old <- cache_stats_defaults[[stat]]
     if (!is.null(old)) {
       new <- update_stat_defaults(stat, old)
-      env_unbind(cache_stats_defaults, stat)
     }
     invisible(new)