Following the reproduction instructions from
https://github.com/i3/i3/issues/3242#issuecomment-436175346
For me, #3242 happened when the following sequence executed:
1. Fullscreening window correctly calls `stop_child()` in
6e24e2ad6f/i3bar/src/xcb.c (L685)
2. Xrandr change, `reconfig_windows()` is called and `output->visible` is
set to `true` in this line:
6e24e2ad6f/i3bar/src/xcb.c (L1791)
3. When the window's fullscreen is disabled,
`handle_visibility_notify()` returns in this line:
6e24e2ad6f/i3bar/src/xcb.c (L677)
because previously `output->visible` was set to `true`
To fix this, I call `cont_child()` more leniently since it is a no-op
when the child is not stopped.
Fixes#3242Closes#3761
016d4a3f45