graphics.c: Check for empty json file
If we have an empty json file json_node_get_object
will fail.
Add a check before it and return with SRT_GRAPHICS_ISSUES_CANNOT_LOAD
The CI is currently failing because apparently it is using x86_64-linux-gnu-vulkaninfo
from /usr/bin
that returns an empty output.
This leads to an error when we try to parse it as a JSON object.
I'm not sure what caused this issue now that never showed before.
Has vulkan-utils
been added to the CI base image maybe?
/cc @smcv @jpwhiting