5 ms·

I have. Like keeping a copy of the last page you viewed in Chrome and overlaying it on the screen after exiting the browser. That one is fun.

colechristensen 6y ago
I encountered a real fun bug where a game on linux crashed and a ghost of the game remained on the monitor even after it was connected to a different computer and power cycled, it remained for days. Some really interesting cascading bugs there.
- cesarb 6y ago
  That reminds me of the spookiest bug I've ever encountered: once, when resuming a Dell laptop from suspend at work, it showed a Windows desktop. Said laptop had been running Linux exclusively for several months (but it had previously been used with Windows). Interacting with the laptop made the expected xscreensaver unlock screen appear, and everything worked normally afterwards. The only explanation I could come up with was that, somehow, a snapshot of the Windows screen had survived intact in a corner of the framebuffer which the Linux driver didn't touch, even after months of power off/on and suspend/resume cycles, and a bizarre driver glitch made it visible in that particular resume cycle.
  - ateng 6y ago
    The said windows desktop ghost screen didn’t have date time on start menu, did it?
    - cesarb 6y ago
      If I recall correctly, the Windows XP default was to show only the time, so the date probably wasn't visible.
- marcan_42 6y ago
  That's not a software bug, that's an image retention issue with your monitor. If it was that severe then it probably got into a state where it was sending severely invalid timings to the TFT LCD array, DC biasing it, which causes long-term retention and may even cause permanent damage if done for too long. Software isn't supposed to be able to cause that. That's on your monitor.
  - colechristensen 6y ago
    I _think_ it was every other frame, and I am fairly sure that it was a software/driver issue. It had never happened before, it has not happened since, and it started immediately when starting the game and the symptoms got progressively worse and triggering the mild symptoms happened every time I started the game. What I convinced myself of after a few minutes being sure I wasn't hallucinating was that the graphics driver was pushing out malformed data in some way or the other which was triggering bugs in the monitor hardware/firmware, which is easy to believe are plentiful. It would be an interesting project to try to track down and replicate the bug.
xyzzy_plugh 6y ago
I get this on Macbook Pros pretty often when connecting external displays. I think the nvidia drivers are universally bad.

colechristensen 6y ago

I encountered a real fun bug where a game on linux crashed and a ghost of the game remained on the monitor even after it was connected to a different computer and power cycled, it remained for days. Some really interesting cascading bugs there.

cesarb 6y ago
That reminds me of the spookiest bug I've ever encountered: once, when resuming a Dell laptop from suspend at work, it showed a Windows desktop. Said laptop had been running Linux exclusively for several months (but it had previously been used with Windows). Interacting with the laptop made the expected xscreensaver unlock screen appear, and everything worked normally afterwards. The only explanation I could come up with was that, somehow, a snapshot of the Windows screen had survived intact in a corner of the framebuffer which the Linux driver didn't touch, even after months of power off/on and suspend/resume cycles, and a bizarre driver glitch made it visible in that particular resume cycle.
- ateng 6y ago
  The said windows desktop ghost screen didn’t have date time on start menu, did it?
  - cesarb 6y ago
    If I recall correctly, the Windows XP default was to show only the time, so the date probably wasn't visible.
marcan_42 6y ago
That's not a software bug, that's an image retention issue with your monitor. If it was that severe then it probably got into a state where it was sending severely invalid timings to the TFT LCD array, DC biasing it, which causes long-term retention and may even cause permanent damage if done for too long. Software isn't supposed to be able to cause that. That's on your monitor.
- colechristensen 6y ago
  I _think_ it was every other frame, and I am fairly sure that it was a software/driver issue. It had never happened before, it has not happened since, and it started immediately when starting the game and the symptoms got progressively worse and triggering the mild symptoms happened every time I started the game. What I convinced myself of after a few minutes being sure I wasn't hallucinating was that the graphics driver was pushing out malformed data in some way or the other which was triggering bugs in the monitor hardware/firmware, which is easy to believe are plentiful. It would be an interesting project to try to track down and replicate the bug.

xyzzy_plugh 6y ago

I get this on Macbook Pros pretty often when connecting external displays. I think the nvidia drivers are universally bad.