PTZControls::~PTZControls() called SaveConfig(), which calls obs_module_config_path("config.json"). That expands to obs_module_get_config_path(obs_current_module(), file). On Linux, libobs's obs_module_free_all_modules() invokes each module's unload callback and then calls free_module(), which calls set_pointer(NULL) on the module's static obs_module_pointer. From that point on, obs_current_module() returns NULL inside the .so. The Qt-owned dock widget is destroyed later, during the event loop processing of deferred-delete events, so SaveConfig() called from ~PTZControls runs after obs_current_module() has been nulled and crashes inside obs_module_get_config_path on a NULL dereference. As a side effect, recently-changed PTZ state (presets, splitter layout, joystick mapping, device list) is silently lost on those exits. The relative ordering of module unload vs Qt widget destruction is platform-specific (on macOS the dock is destroyed before module unload, the opposite of Linux), so neither the destructor nor obs_module_unload() is a safe place on every platform to perform shutdown work that needs both obs APIs callable AND the dock widget alive. Fix: perform SaveConfig(), hotkey unregister, and device teardown from the OBS_FRONTEND_EVENT_EXIT handler. OBS guarantees that this event fires before any Qt teardown and before any module unload on every platform, so both prerequisites are met. settings.cpp already uses this same pattern to tear down the PTZSettings window. The frontend-event wrapper handles EXIT synchronously rather than queuing through the Qt event loop, to ensure the work completes before Qt begins tearing down widgets. Two open issues report the original crash symptom: - glikely#274 OBS Crashing with PTZ Plugin: user sees OBS crash on every close, leaving a zombied process behind on Windows. - glikely#285 Periodically save changes to presets instead of waiting until shutdown: user reports presets lost on exit and "OBS Exit crashes are also happening"; previously suspected to be caused by another plugin, but the actual crash is here in obs-ptz itself. Tested on Linux Mint 22.3 / Ubuntu noble with obs-studio 32.1.2 from the official OBS PPA and obs-ptz v0.18.2 + this patch. Before the patch, every OBS shutdown produced a SIGSEGV core dump with the backtrace below; after the patch, OBS exits cleanly and config saves correctly on exit: #0 obs_module_get_config_path (libobs) glikely#1-3 obs-ptz.so (PTZControls::SaveConfig -> obs_module_config_path) glikely#4 QObjectPrivate::deleteChildren (Qt6Core) glikely#5 QWidget::~QWidget (Qt6Widgets) The macOS code path has not been tested on hardware, but the EXIT event approach matches the existing pattern in settings.cpp, which has been the canonical shutdown hook in this codebase for the same ordering reasons. Closes glikely#274 Closes glikely#285 Signed-off-by: Sam Mallon <samuel.mallon@gmail.com> Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Request: Periodically save changes to presets instead of waiting until shutdown #285

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