From d7ea1b7785f31e9fd6477490309721a19a835592 Mon Sep 17 00:00:00 2001
From: Tom Englund <tomenglund26@gmail.com>
Date: Mon, 1 Jul 2024 00:26:08 +0200
Subject: [PATCH] xwayland: break cyclic loop of parents (#6722)

in X11 some surfaces is a parent of itself and creates a cyclic loop
when trying to find its parent. check for old parent and break if its
beginning to roll over.
---
 src/desktop/Window.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/desktop/Window.cpp b/src/desktop/Window.cpp
index e67a3357..560e5103 100644
--- a/src/desktop/Window.cpp
+++ b/src/desktop/Window.cpp
@@ -444,9 +444,11 @@ PHLWINDOW CWindow::X11TransientFor() {
     if (!m_pXWaylandSurface || !m_pXWaylandSurface->parent)
         return nullptr;
 
-    auto s = m_pXWaylandSurface->parent;
+    auto s         = m_pXWaylandSurface->parent;
+    auto oldParent = s;
     while (s) {
-        if (!s->parent)
+        // break cyclic loop of m_pXWaylandSurface being parent of itself, #TODO reject this from even being created?
+        if (!s->parent || s->parent == oldParent)
             break;
         s = s->parent;
     }