[education/rkward] rkward/rbackend: Add missing mutex lock

[Thomas Friedrichsmeier]

Git commit 5164e48f2b975df128568970769a8c0729b586d5 by Thomas Friedrichsmeier.
Committed on 12/09/2025 at 20:56.
Pushed by tfry into branch 'master'.

Add missing mutex lock

M  +2    -0    rkward/rbackend/rkrbackend.cpp

https://invent.kde.org/education/rkward/-/commit/5164e48f2b975df128568970769a8c0729b586d5

diff --git a/rkward/rbackend/rkrbackend.cpp b/rkward/rbackend/rkrbackend.cpp
index 8e541c79b..4f0a5c345 100644
--- a/rkward/rbackend/rkrbackend.cpp
+++ b/rkward/rbackend/rkrbackend.cpp
@@ -1320,8 +1320,10 @@ void doPendingPriorityCommands() {
 	RK_TRACE(RBACKEND);
 
 	if (RKRBackend::this_pointer->killed) return;
+	RKRBackend::this_pointer->priority_command_mutex.lock();
 	RCommandProxy *command = RKRBackend::this_pointer->pending_priority_command;
 	RKRBackend::this_pointer->pending_priority_command = nullptr;
+	RKRBackend::this_pointer->priority_command_mutex.unlock();
 	if (command) {
 		RK_DEBUG(RBACKEND, DL_DEBUG, "running priority command %s", qPrintable(command->command));
 		{