Bug 449194

SUMMARY
after I crazily move my cursor among diferent tasks to show window thumbnails in tooltips. It seems there is a maximum number of screen casting requests a program can make.

coredumpctl shows no record on the crash.

STEPS TO REPRODUCE
1. Login to a Wayland session
2. Move the cursor to hover on different tasks to show tooltips repeatedly

OBSERVED RESULT
plasmashell crashes

EXPECTED RESULT
No crash

SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20220124
KDE Plasma Version: 5.24.80
KDE Frameworks Version: 5.91.0
Qt Version: 5.15.2
Kernel Version: 5.16.1-1-default (64-bit)
Graphics Platform: Wayland
Processors: 8 × AMD Ryzen 7 4700U with Radeon Graphics
Memory: 15.0 GiB of RAM
Graphics Processor: AMD RENOIR

ADDITIONAL INFORMATION
Log when plasmashell crashed

```
1月 26 19:45:40 ZHAN66 kwin_wayland[3281]: kwin_screencast: PipeWire remote error:  connection error
1月 26 19:45:40 ZHAN66 wireplumber[2452]: <WpSiStandardLink:0x7f5498007ec0> 1 of 1 PipeWire links failed to activate
1月 26 19:45:40 ZHAN66 wireplumber[2452]: <WpSiStandardLink:0x55f82bab1540> 1 of 1 PipeWire links failed to activate
1月 26 19:45:41 ZHAN66 kwin_wayland[3281]: kwin_screencast: Could not connect to stream
1月 26 19:45:41 ZHAN66 kwin_wayland[3281]: kwin_screencast: Failed to create PipeWire stream
1月 26 19:45:41 ZHAN66 kwin_wayland[3281]: kwin_screencast: Could not connect to stream
1月 26 19:45:41 ZHAN66 kwin_wayland[3281]: kwin_screencast: Failed to create PipeWire stream
1月 26 19:45:41 ZHAN66 plasmashell[5261]: error creating screencast "Failed to create PipeWire stream"
1月 26 19:45:41 ZHAN66 plasmashell[5261]: error creating screencast "Failed to create PipeWire stream"
1月 26 19:45:41 ZHAN66 kwin_wayland_wrapper[3281]: file descriptor expected, object (1124), message add(huuuuu)
1月 26 19:45:41 ZHAN66 kwin_wayland_wrapper[3281]: error in client communication (pid 5261)
1月 26 19:45:41 ZHAN66 kwin_wayland[3281]: QMetaProperty::read: Unable to handle unregistered datatype 'KWin::SessionState' for property 'KWin::EffectsHandlerImpl::sessionState'
1月 26 19:45:41 ZHAN66 plasmashell[5261]: wl_display@1: error 1: invalid arguments for zwp_linux_buffer_params_v1@1124.add
1月 26 19:45:41 ZHAN66 plasmashell[5261]: The Wayland connection experienced a fatal error: 无效的参数
1月 26 19:45:41 ZHAN66 plasmashell[5261]: The Wayland connection experienced a fatal error: 无效的参数
1月 26 19:45:41 ZHAN66 kded5[3647]: Service  "org.kde.StatusNotifierHost-5261" unregistered
1月 26 19:45:41 ZHAN66 systemd[2051]: plasma-plasmashell.service: Main process exited, code=exited, status=1/FAILURE
1月 26 19:45:41 ZHAN66 systemd[2051]: plasma-plasmashell.service: Failed with result 'exit-code'.
1月 26 19:45:41 ZHAN66 systemd[2051]: plasma-plasmashell.service: Consumed 7.836s CPU time.
1月 26 19:45:41 ZHAN66 systemd[2051]: plasma-plasmashell.service: Scheduled restart job, restart counter is at 3.
1月 26 19:45:41 ZHAN66 systemd[2051]: Stopped KDE Plasma Workspace.
```

无效的参数 means "invalid arguments".