Missing autostart file causes repeated cs-backup-locker segfault, exhausting X11 client connections

### Distribution Mint 22.3 ### Package version 6.6.1 ### Graphics hardware in use NVIDIA GeForce RTX 3070 ### Frequency Quite often ### Bug description Lately my computer has stopped locking it screen, maybe for the past couple days. I noticed that it's also become slower and slower to open apps as well. Not being well-versed in debug Linux issues I turned to Claude to troubleshoot. Claude suspected that maybe screensaver was broken or crashing. After some debugging, found that X11 had too many sessions open and refused to open anymore. ``` $ xhost Maximum number of clients reached xhost: unable to open display ":0" ``` Then tried to see if screensaver was even running: ``` $ systemctl --user status cinnamon-screensaver Unit cinnamon-screensaver.service could not be found. ``` > The service unit file is missing entirely — the update almost certainly removed or broke the cinnamon-screensaver package. Skipping ahead, we determined that it is installed and without errors but the autostart is busted. `$ dpkg -L cinnamon-screensaver | grep autostart` It returns no output. This issue sounds similar but I don't know if it's the same: https://github.com/linuxmint/cinnamon-screensaver/issues/501 . Claude was saying that maybe because the autostart is invalid it's not starting properly when it needs to. Looking in the ~/.xsession-errors I saw this: ``` (csd-automount:4272): csd-automount-WARNING **: 00:20:10.223: Can't call GetActive() on the ScreenSaver object: Cannot invoke method; proxy is for the well-known name org.cinnamon.ScreenSaver without an owner, and proxy was constructed with the G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START flag ``` Here is with the debug command: ``` $ cinnamon-screensaver --debug --hold Loading AccountsService Fractional scaling active: False Trying to connect to logind... Starting screensaver... Debug mode active Cinnamon Screensaver support not found in current theme - adding some... service: 'GetActive' received, poking application. service: 'GetActive' received, poking application. service: 'GetActive' received, poking application. org.gnome.ScreenSaver is gone from the session bus org.mate.ScreenSaver is gone from the session bus service: 'GetActive' received, poking application. AccountsService ready login client: found session path for user 'ace' (session_id: c2): /org/freedesktop/login1/session/c2 Successfully using logind ``` It also does look like it crashed, here is the pastebin for the crash: https://termbin.com/f0rp I asked Claude to explain if this is related to my X11 issue and it says it is, I don't know enough to say otherwise but I'll toss it in here for context. > any of this relate to the x11 issue? > > Yes, directly. Here's the chain: > > 1. No autostart file → cinnamon-screensaver never launches at login > 2. csd-screensaver-proxy starts (it's the only thing with an autostart file) and sits there waiting for org.cinnamon.ScreenSaver to appear on D-Bus > 3. Other components like csd-automount also poll org.cinnamon.ScreenSaver repeatedly via D-Bus > 4. Since nothing ever registers as org.cinnamon.ScreenSaver, D-Bus activation kicks in each time — it spawns cinnamon-screensaver on demand to handle the request > 5. That spawned instance tries to start, hits the cs-backup-locker segfault, and dies > 6. The cycle repeats — each failed attempt leaves behind dead X11 client connections > 7. Eventually all 256 X11 client slots are exhausted → every new app times out for 30 seconds trying to connect > > So the segfault in cs-backup-locker is actually the direct cause of the X11 connection leak. Each crash leaves a dangling connection. The missing autostart file is what triggers the repeated crash-restart cycle in the first place. I dunno if any of this is helpful or should be in the #501 ticket but figured I should report it regardless. Thanks ### Steps to reproduce Wait until screen tries to lock i suppose ### Expected behavior The screen to lock ### Additional information _No response_