screencopy/toplevelexport: sanitize pointers in ::copyFrame

oopsie~~ >///<

1 files changed, 7 insertions, 0 deletions

diff --git a/src/protocols/Screencopy.cpp b/src/protocols/Screencopy.cpp
index 18fe09f4..5f8c00d4 100644
--- a/src/protocols/Screencopy.cpp
+++ b/src/protocols/Screencopy.cpp
@@ -191,6 +191,13 @@ void CScreencopyProtocolManager::captureOutput(wl_client* client, wl_resource* r
     PFRAME->resource      = wl_resource_create(client, &zwlr_screencopy_frame_v1_interface, wl_resource_get_version(resource), frame);
     PFRAME->pMonitor      = g_pCompositor->getMonitorFromOutput(wlr_output_from_resource(output));
 
+    if (!g_pCompositor->monitorExists(PFRAME->pMonitor)) {
+        Debug::log(ERR, "client requested sharing of a monitor that is gone");
+        zwlr_screencopy_frame_v1_send_failed(PFRAME->resource);
+        removeFrame(PFRAME);
+        return;
+    }
+
     if (!PFRAME->pMonitor) {
         Debug::log(ERR, "client requested sharing of a monitor that doesnt exist");
         zwlr_screencopy_frame_v1_send_failed(PFRAME->resource);