From ceb26d9fc91b65f4274c38c97490542d2865bc83 Mon Sep 17 00:00:00 2001
From: Hadley Wickham <h.wickham@gmail.com>
Date: Wed, 10 Jan 2024 08:53:31 -0600
Subject: [PATCH] Restore previously opened device (#245)

Fixes #138
---
 NEWS.md                       |  3 +++
 R/devices.R                   | 49 +++++++++++++++++++++--------------
 tests/testthat/helper.R       |  4 +++
 tests/testthat/test-devices.R | 13 ++++++++++
 4 files changed, 49 insertions(+), 20 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index 559041cb..ad581340 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,8 @@
 # withr (development version)
 
+* `local_pdf()` and friends now correctly restore to the previously 
+  active device (#138).
+
 * `local_()` now works even if withr isn't attached (#207).
 
 * `defer()` is now a thin wrapper around `base::on.exit()`. This is
diff --git a/R/devices.R b/R/devices.R
index b74869e5..2dd1a8be 100644
--- a/R/devices.R
+++ b/R/devices.R
@@ -77,40 +77,49 @@ jpeg_dev <- function(filename, ...) {
 #' )
 NULL
 
+dev_close <- function(which) {
+  prev <- dev.prev(which)
+  grDevices::dev.off(which)
+  if (prev != which) # no devices active
+    dev.set(prev)
+
+  prev
+}
+
 #' @describeIn devices BMP device
 #' @export
-with_bmp <- with_(bmp_dev, grDevices::dev.off)
+with_bmp <- with_(bmp_dev, dev_close)
 
 #' @rdname devices
 #' @export
-local_bmp <- local_(bmp_dev, grDevices::dev.off)
+local_bmp <- local_(bmp_dev, dev_close)
 
 #' @describeIn devices CAIRO_PDF device
 #' @inheritParams grDevices::cairo_pdf
 #' @export
-with_cairo_pdf <- with_(cairo_pdf_dev, grDevices::dev.off)
+with_cairo_pdf <- with_(cairo_pdf_dev, dev_close)
 
 #' @rdname devices
 #' @export
-local_cairo_pdf <- local_(cairo_pdf_dev, grDevices::dev.off)
+local_cairo_pdf <- local_(cairo_pdf_dev, dev_close)
 
 #' @describeIn devices CAIRO_PS device
 #' @inheritParams grDevices::cairo_ps
 #' @export
-with_cairo_ps <- with_(cairo_ps_dev, grDevices::dev.off)
+with_cairo_ps <- with_(cairo_ps_dev, dev_close)
 
 #' @rdname devices
 #' @export
-local_cairo_ps <- local_(cairo_ps_dev, grDevices::dev.off)
+local_cairo_ps <- local_(cairo_ps_dev, dev_close)
 
 #' @describeIn devices PDF device
 #' @inheritParams grDevices::pdf
 #' @export
-with_pdf <- with_(pdf_dev, grDevices::dev.off)
+with_pdf <- with_(pdf_dev, dev_close)
 
 #' @rdname devices
 #' @export
-local_pdf <- local_(pdf_dev, grDevices::dev.off)
+local_pdf <- local_(pdf_dev, dev_close)
 
 #' @describeIn devices POSTSCRIPT device
 #' @inheritParams grDevices::postscript
@@ -119,51 +128,51 @@ local_pdf <- local_(pdf_dev, grDevices::dev.off)
 #'   length limit is \code{2*PATH_MAX}, typically 8096 bytes on unix systems and
 #'   520 bytes on windows.
 #' @export
-with_postscript <- with_(postscript_dev, grDevices::dev.off)
+with_postscript <- with_(postscript_dev, dev_close)
 
 #' @rdname devices
 #' @export
-local_postscript <- local_(postscript_dev, grDevices::dev.off)
+local_postscript <- local_(postscript_dev, dev_close)
 
 #' @describeIn devices SVG device
 #' @inheritParams grDevices::svg
 #' @export
-with_svg <- with_(svg_dev, grDevices::dev.off)
+with_svg <- with_(svg_dev, dev_close)
 
 #' @rdname devices
 #' @export
-local_svg <- local_(svg_dev, grDevices::dev.off)
+local_svg <- local_(svg_dev, dev_close)
 
 #' @describeIn devices TIFF device
 #' @export
-with_tiff <- with_(tiff_dev, grDevices::dev.off)
+with_tiff <- with_(tiff_dev, dev_close)
 
 
 #' @rdname devices
 #' @export
-local_tiff <- local_(tiff_dev, grDevices::dev.off)
+local_tiff <- local_(tiff_dev, dev_close)
 
 #' @describeIn devices XFIG device
 #' @inheritParams grDevices::xfig
 #' @export
-with_xfig <- with_(xfig_dev, grDevices::dev.off)
+with_xfig <- with_(xfig_dev, dev_close)
 
 #' @rdname devices
 #' @export
-local_xfig <- local_(xfig_dev, grDevices::dev.off)
+local_xfig <- local_(xfig_dev, dev_close)
 
 #' @describeIn devices PNG device
 #' @export
-with_png <- with_(png_dev, grDevices::dev.off)
+with_png <- with_(png_dev, dev_close)
 
 #' @rdname devices
 #' @export
-local_png <- local_(png_dev, grDevices::dev.off)
+local_png <- local_(png_dev, dev_close)
 
 #' @describeIn devices JPEG device
 #' @export
-with_jpeg <- with_(jpeg_dev, grDevices::dev.off)
+with_jpeg <- with_(jpeg_dev, dev_close)
 
 #' @rdname devices
 #' @export
-local_jpeg <- local_(jpeg_dev, grDevices::dev.off)
+local_jpeg <- local_(jpeg_dev, dev_close)
diff --git a/tests/testthat/helper.R b/tests/testthat/helper.R
index b8f6cdce..a90b3cbf 100644
--- a/tests/testthat/helper.R
+++ b/tests/testthat/helper.R
@@ -1,3 +1,7 @@
+set_state_inspector(function() {
+  dir(".")
+})
+
 expect_no_output <- function(...) {
   testthat::expect_output(..., regexp = NA)
 }
diff --git a/tests/testthat/test-devices.R b/tests/testthat/test-devices.R
index 6a53962e..28588463 100644
--- a/tests/testthat/test-devices.R
+++ b/tests/testthat/test-devices.R
@@ -77,3 +77,16 @@ test_that("local_device functions create a plot file", {
 
   unlink(plot_dir)
 })
+
+test_that("multiple devices closed in correct order", {
+  dev1 <- local_pdf(tempfile())
+
+  local({
+    dev2 <- local_pdf(tempfile())
+
+    local(withr::local_pdf(tempfile()))
+    expect_equal(dev.cur(), dev2)
+  })
+
+  expect_equal(dev.cur(), dev1)
+})