[FFmpeg-devel] [PATCH v4] avdevice/xcbgrab: check return values of xcb query functions

Since xcbgrab is getting some attention recently... Fixes a segfault, as reported in #7312. To reproduce: Terminal 1: $ Xvfb :1 -nolisten tcp -screen 0 800x600x24 Terminal 2: $ ffmpeg -f x11grab -i :1 -f null - or rather $ gdb -ex r --args ffmpeg_g -f x11grab -i :1 -f null - Then terminate Xvfb while ffmpeg is running. Cheers, Moritz