[education/rkward] /: Circumvent race condition around detection of changed output

[Thomas Friedrichsmeier]

Git commit 8fe1503fd2d97175efe498e0bcb3a68c2a555169 by Thomas Friedrichsmeier.
Committed on 10/10/2025 at 15:50.
Pushed by tfry into branch 'master'.

Circumvent race condition around detection of changed output

See https://invent.kde.org/education/rkward/-/issues/49

Not entirely a fix for the underlying problem, but makes this
(non-fatal) condition very much less likely to trigger

M  +1    -0    ChangeLog
M  +1    -1    VERSION.cmake
M  +1    -4    rkward/plugin/rkpreviewbox.cpp
M  +1    -1    rkward/rbackend/rpackages/rkward/DESCRIPTION
M  +12   -8    rkward/rbackend/rpackages/rkward/R/rk.filename-functions.R

https://invent.kde.org/education/rkward/-/commit/8fe1503fd2d97175efe498e0bcb3a68c2a555169

diff --git a/ChangeLog b/ChangeLog
index 7c199053d..39dc12aed 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,5 @@
 --- Version 0.8.3 - UNRELEASED
+- Fixed: Output window would fail to open, automatically, for certain plugins
 - Fixed: Width of "progress" dialogs (showing R output) would exceed screen size depending on configuration
 
 --- Version 0.8.2 - Oct-01-2025
diff --git a/VERSION.cmake b/VERSION.cmake
index 03d965675..51713d0c9 100644
--- a/VERSION.cmake
+++ b/VERSION.cmake
@@ -1,3 +1,3 @@
 # DO NOT CHANGE THIS FILE MANUALLY!
 # It will be overwritten by scripts/set_dist_version.sh
-SET(RKVERSION_NUMBER 0.8.2z+0.8.3+devel1)
+SET(RKVERSION_NUMBER 0.8.2z+0.8.3+devel2)
diff --git a/rkward/plugin/rkpreviewbox.cpp b/rkward/plugin/rkpreviewbox.cpp
index 052264f5a..1295660c1 100644
--- a/rkward/plugin/rkpreviewbox.cpp
+++ b/rkward/plugin/rkpreviewbox.cpp
@@ -75,10 +75,7 @@ RKPreviewBox::RKPreviewBox(const QDomElement &element, RKComponent *parent_compo
 				                                        "outfile <- tempfile (fileext='.html')\n"
 				                                        "rk.assign.preview.data(") +
 				                             idprop + QStringLiteral(", list (filename=outfile, on.delete=function (id) {\n"
-				                                                     "	oldfile <- rk.get.output.html.file()\n"
-				                                                     "	rk.flush.output(outfile, ask=FALSE)\n"
-				                                                     "	unlink(outfile)\n"
-				                                                     "	rk.set.output.html.file(oldfile)\n"
+				                                                     "	rkward:::.rk.discard.output(outfile)\n"
 				                                                     "}))\n"
 				                                                     "oldfile <- rk.set.output.html.file (outfile, style='preview')  # for initialization\n"
 				                                                     "rk.set.output.html.file (oldfile)\n"
diff --git a/rkward/rbackend/rpackages/rkward/DESCRIPTION b/rkward/rbackend/rpackages/rkward/DESCRIPTION
index 2373701cf..9ba922832 100755
--- a/rkward/rbackend/rpackages/rkward/DESCRIPTION
+++ b/rkward/rbackend/rpackages/rkward/DESCRIPTION
@@ -15,7 +15,7 @@ LazyLoad: yes
 Authors at R: c(person(given="Thomas", family="Friedrichsmeier", email="thomas.friedrichsmeier at kdemail.net", role=c("aut")), person(given="the RKWard", family="team",
                     email="rkward at kde.org", role=c("cre","aut")))
 Version: 0.8.3
-Date: 2025-09-26
+Date: 2025-10-10
 RoxygenNote: 7.3.3
 Collate: 
     'base_overrides.R'
diff --git a/rkward/rbackend/rpackages/rkward/R/rk.filename-functions.R b/rkward/rbackend/rpackages/rkward/R/rk.filename-functions.R
index e1eb50cf1..e15b8283c 100644
--- a/rkward/rbackend/rpackages/rkward/R/rk.filename-functions.R
+++ b/rkward/rbackend/rpackages/rkward/R/rk.filename-functions.R
@@ -256,15 +256,14 @@
 	files
 }
 
-#' @export
-#' @rdname rk.get.tempfile.name
-"rk.flush.output" <- function (x=rk.get.output.html.file (), flush.images=TRUE, ask=TRUE, ...) {
-	images <- character (0)
-	if (flush.images) images <- .rk.get.images.in.html.file (x)
+# not exported, but used by interal preview code
+".rk.discard.output" <- function(x, flush.images=TRUE, ask=FALSE) {
+	images <- character(0)
+	if (flush.images) images <- .rk.get.images.in.html.file(x)
 
 	desc <- x
-	if (length (images)) {
-		desc <- paste (x, ", along with ", length (images), " image files", sep="")
+	if (length(images)) {
+		desc <- paste(x, ", along with ", length(images), " image files", sep="")
 	}
 
 	if (isTRUE (ask)) {
@@ -277,8 +276,13 @@
 			unlink (image)
 		}
 	)
+}
 
-	rk.set.output.html.file (x, ...)
+#' @export
+#' @rdname rk.get.tempfile.name
+"rk.flush.output" <- function(x=rk.get.output.html.file(), flush.images=TRUE, ask=TRUE, ...) {
+	.rk.discard.output(x, flush.images, ask)
+	rk.set.output.html.file(x, ...)
 }
 
 #' Evaluate the given input file, recording a transcript to an HTML output file (including on-screen plots)