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Remove crashy unwrap() in on_error #1364

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5 changes: 4 additions & 1 deletion src/decode.rs
Original file line number Diff line number Diff line change
Expand Up @@ -4994,7 +4994,10 @@ pub fn rav1d_submit_frame(c: &Rav1dContext, state: &mut Rav1dState) -> Rav1dResu
) {
fc.task_thread.error.store(1, Ordering::Relaxed);
let _ = mem::take(&mut *fc.in_cdf.try_write().unwrap());
if f.frame_hdr.as_ref().unwrap().refresh_context != 0 {
if f.frame_hdr
.as_ref()
.is_some_and(|frame_hdr| frame_hdr.refresh_context != 0)
{
Comment on lines +4997 to +5000
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I'm not sure what the right behavior is in the None case, but crashing is certainly not it

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Places where there is an unwrap should have been unchecked derefs in C, so let me check what C was doing here.

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So C is doing the same thing as we are here:

Can you check if you get an error/crash on dav1d here or not? Thanks!

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@emilk emilk Oct 4, 2024

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Using https://crates.io/crates/dav1d 0.10.3 I do not get a crash, but I get an Invalid argument error and some useful info printed:

Error parsing frame header
Error parsing OBU data

It should be noted though that dereferencing a null pointer is not necessarily a crash in C - it is Undefined Behavior. The compiler is free to assume the pointer is not null, and do whatever crazy shenanigans that implies.

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Hmm, it's possible UB could be doing something weird here, but I'd still expect a segfault for the most part. We likely diverged at some point, so we'll have to figure out where and see if that's something we need to fix or if it's okay to crash, just in a different place.

That said, this video should successfully decode with normal dav1d, but doesn't? Is that a bug with dav1d as well?

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@emilk emilk Oct 7, 2024

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or if it's okay to crash

I would prefer a rav1d that never crashes on any input, but returns errors.

That said, this video should successfully decode with normal dav1d, but doesn't? Is that a bug with dav1d as well?

I don't know if the video should successfully decode, or if it is actually a bad video.

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I would prefer a rav1d that never crashes on any input, but returns errors.

Yup, that would definitely be preferable.

let _ = mem::take(&mut f.out_cdf);
}
for i in 0..7 {
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