From 5ecd8393a22f9162c2ff00bd1b9cbd0b17b43ea3 Mon Sep 17 00:00:00 2001
From: neonetizen <justin@neonetizen.net>
Date: Thu, 21 May 2026 12:30:39 -0700
Subject: [PATCH] internal: fix null deref in setWindowFullscreenInternal when
 fullscreen state stale (#14725)

---
 src/Compositor.cpp                            | 2 ++
 src/desktop/view/Window.cpp                   | 4 ++++
 src/managers/screenshare/ScreenshareFrame.cpp | 7 +++++--
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/Compositor.cpp b/src/Compositor.cpp
index d2fe2f9c8..54c60b212 100644
--- a/src/Compositor.cpp
+++ b/src/Compositor.cpp
@@ -2196,6 +2196,8 @@ void CCompositor::changeWindowFullscreenModeClient(const PHLWINDOW PWINDOW, cons
 
 // TODO: move fs functions to Desktop::
 void CCompositor::setWindowFullscreenInternal(const PHLWINDOW PWINDOW, const eFullscreenMode MODE) {
+    if (!PWINDOW)
+        return;
     if (PWINDOW->m_ruleApplicator->syncFullscreen().valueOrDefault())
         setWindowFullscreenState(PWINDOW, Desktop::View::SFullscreenState{.internal = MODE, .client = MODE});
     else
diff --git a/src/desktop/view/Window.cpp b/src/desktop/view/Window.cpp
index eb7e171ec..635da1e08 100644
--- a/src/desktop/view/Window.cpp
+++ b/src/desktop/view/Window.cpp
@@ -1820,6 +1820,10 @@ void CWindow::mapWindow() {
         Desktop::focusState()->rawMonitorFocus(g_pCompositor->getMonitorFromVector({}));
         PMONITOR = Desktop::focusState()->monitor();
     }
+    if (!PMONITOR || (!PMONITOR->m_activeSpecialWorkspace && !PMONITOR->m_activeWorkspace)) {
+        Log::logger->log(Log::ERR, "mapWindow: no valid monitor/workspace, aborting map for {:x}", (uintptr_t)this);
+        return;
+    }
     auto PWORKSPACE = PMONITOR->m_activeSpecialWorkspace ? PMONITOR->m_activeSpecialWorkspace : PMONITOR->m_activeWorkspace;
     m_monitor       = PMONITOR;
     m_workspace     = PWORKSPACE;
diff --git a/src/managers/screenshare/ScreenshareFrame.cpp b/src/managers/screenshare/ScreenshareFrame.cpp
index 4cc51335e..69d4ba65a 100644
--- a/src/managers/screenshare/ScreenshareFrame.cpp
+++ b/src/managers/screenshare/ScreenshareFrame.cpp
@@ -29,8 +29,11 @@ CScreenshareFrame::~CScreenshareFrame() {
     if (m_failed || !m_shared)
         return;
 
-    if (!m_copied && m_callback)
-        m_callback(RESULT_NOT_COPIED);
+    if (!m_copied && m_callback) {
+        FScreenshareCallback cb;
+        std::swap(cb, m_callback);
+        cb(RESULT_NOT_COPIED);
+    }
 }
 
 bool CScreenshareFrame::done() const {