From 39ac19f7c8a61451ce386d386c87182415d62eab Mon Sep 17 00:00:00 2001
From: Wehrwolfmann <256216494+wehrwolfmann@users.noreply.github.com>
Date: Sat, 22 Aug 2026 23:58:01 +0200
Subject: [PATCH] Keep Qt's own message dialogs on Plasma

On Plasma our message boxes go through KDEPlatformMessageDialogHelper. It
creates its own QMessageBox, sets Qt::WA_DeleteOnClose on it and keeps a raw
pointer to it. QDialog::exec() deletes that dialog when it closes, so the
helper is left with a dangling pointer; the later hide() call from
~QMessageBox dereferences freed memory and kills the app with SIGSEGV.

The defect is in plasma-integration, but every QMessageBox in the app is
exposed to it, so keep Qt's own dialogs instead. Nothing changes visually -
the "native" Plasma dialog is a QMessageBox as well.

Measured with the patch: 10 About/License cycles under a debugger, zero
helper dialogs created and zero setNativeDialogVisible calls. Without it the
helper dialog is created and destroyed before our own box on every click.
---
 src/main.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/main.cpp b/src/main.cpp
index bd9fb40..a1b964a 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -138,6 +138,12 @@ auto main(int argc, char** argv) -> std::int32_t {
     QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
 #endif
 
+    // Keep using Qt's own dialogs. The Plasma platform theme creates a helper QMessageBox
+    // for every native message dialog, marks it WA_DeleteOnClose and keeps a raw pointer
+    // to it. QDialog::exec() deletes that helper dialog when it closes, so the later
+    // hide() call from ~QMessageBox dereferences freed memory and can kill the app.
+    QApplication::setAttribute(Qt::AA_DontUseNativeDialogs);
+
     /// 2. Application identification
     QApplication::setOrganizationName("cachyos");
     QApplication::setOrganizationDomain("cachyos.org");