From a1718132971b73d8a86d33c3867daecc0f0584bf Mon Sep 17 00:00:00 2001
From: Kara Woo <woo.kara@gmail.com>
Date: Tue, 6 Oct 2020 17:27:37 -0700
Subject: [PATCH 1/3] If plot theme background is null, set to transparent when
 saving

---
 R/save.r | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/R/save.r b/R/save.r
index 1bdd11381c..a97b35ebbb 100644
--- a/R/save.r
+++ b/R/save.r
@@ -88,6 +88,9 @@ ggsave <- function(filename, plot = last_plot(),
   }
   if (is_null(bg)) {
     bg <- calc_element("plot.background", plot_theme(plot))$fill
+    if (is_null(bg)) {
+      bg <- "transparent"
+    }
   }
   old_dev <- grDevices::dev.cur()
   dev(filename = filename, width = dim[1], height = dim[2], bg = bg, ...)

From dbcf3f14ea33a3ac93076018ce77832a7b4cb03c Mon Sep 17 00:00:00 2001
From: Kara Woo <woo.kara@gmail.com>
Date: Mon, 19 Oct 2020 17:53:29 -0700
Subject: [PATCH 2/3] Add test for svg with no background

---
 tests/testthat/test-ggsave.R | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tests/testthat/test-ggsave.R b/tests/testthat/test-ggsave.R
index 6d60439686..135a112da3 100644
--- a/tests/testthat/test-ggsave.R
+++ b/tests/testthat/test-ggsave.R
@@ -46,6 +46,21 @@ test_that("ggsave uses theme background as image background", {
   expect_true(grepl("fill: #00CCCC", bg))
 })
 
+test_that("ggsave can handle blank background", {
+  skip_if_not_installed("xml2")
+
+  path <- tempfile()
+  on.exit(unlink(path))
+  p <- ggplot(mtcars, aes(disp, mpg)) +
+    geom_point() +
+    theme(plot.background = element_blank())
+  ggsave(path, p, device = "svg", width = 5, height = 5)
+  img <- xml2::read_xml(path)
+  bg <- as.character(xml2::xml_find_first(img, xpath = "d1:rect/@style"))
+  expect_true(grepl("fill: none", bg))
+})
+
+
 # plot_dim ---------------------------------------------------------------
 
 test_that("guesses and informs if dim not specified", {

From 0f3cd8a13fb0aa76c5e790ed8dcc773517d3f95c Mon Sep 17 00:00:00 2001
From: Kara Woo <woo.kara@gmail.com>
Date: Wed, 21 Oct 2020 16:58:46 -0700
Subject: [PATCH 3/3] Make checking for NULL background more concise with %||%

---
 R/save.r | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/R/save.r b/R/save.r
index a97b35ebbb..98bd10e99a 100644
--- a/R/save.r
+++ b/R/save.r
@@ -87,10 +87,7 @@ ggsave <- function(filename, plot = last_plot(),
     filename <- file.path(path, filename)
   }
   if (is_null(bg)) {
-    bg <- calc_element("plot.background", plot_theme(plot))$fill
-    if (is_null(bg)) {
-      bg <- "transparent"
-    }
+    bg <- calc_element("plot.background", plot_theme(plot))$fill %||% "transparent"
   }
   old_dev <- grDevices::dev.cur()
   dev(filename = filename, width = dim[1], height = dim[2], bg = bg, ...)