Forwarding https://bugs.debian.org/547127

I just tested cheese 3.18.1-2 from Debian stretch when inserting a USB camera into a laptop with an integrated camera and a desktop without a camera.

On the desktop:

Plugging in the USB camera while cheese was running didn't give me an image until I restarted cheese. When I removed it I got "There was an error playing video from the webcam" (instead of "No device found"). When I plugged it back in again the error didn't change.

On the laptop:

Plugging in the USB camera while cheese was running let me display video from the USB camera, but only if I went into the preferences. I expect non-technical users would be confused by this. One way to fix this might be to overlay an icon indicating more cameras are available, or small square of video for each one, up to a limit. These could then allow users to switch easily. Alternatively, maybe the world of smartphones has some ideas for the situation of multiple cameras present on a device.

Removing the USB camera while it was capturing video causes the phrase "There was an error playing video from the webcam" to be shown and when that happens, cheese will not show images from neither the USB camera nor the integrated camera until I restart cheese then it worked again. Plugging in the camera again and switching in the preferences does not fix this.