make_current should fail on noop output

[emersion]

Making it succeed can trick the caller into thinking it can render.

@ammen99 Thoughts?

[ammen99]

I am fine with such a change, since the typical scenario is to use make_current when you get a frame event (which you don't get for noop outputs anyway).

The only other place where make_current is used is in wlr_output_preferred_read_format. The read_format in turn is called only in wlr_screencopy_v1.c which will trigger an assertation failure on outputs without renderers (seems like there is an implicit assumption that noop outputs shouldn't be exposed to clients?)

[emersion]

Ah, indeed. Screen capture interfaces should probably stop assuming all outputs have a renderer.