Canvas::fill_rect does not work at all

[avitran0]

i don't know if this is an issue with this crate or sdl3-sys, but Canvas::fill_rect does not work at all, when passing in an FRect. draw_rect works just fine.

System:
Fedora 41
Wayland
Nvidia RTX 3080

using version 0.11 and feature build-from-source

[jajo-11]

Can reproduce on Windows using 483fde4 and build-from-source

replacing the implementation with the following fixes the issue but I am not sure what is actually wrong with the current implementation

#[doc(alias = "SDL_RenderFillRect")]
pub fn fill_rect<R: Into<Option<FRect>>>(&mut self, rect: R) -> Result<(), String> {
    let result= if let Some(rect) = rect.into() {
        unsafe {
            sys::render::SDL_RenderFillRect(
                self.context.raw,
                &rect.to_ll(),
            )
        }
    } else {
        unsafe {
            sys::render::SDL_RenderFillRect(
                self.context.raw,
                ptr::null(),
            )
        }
    };
    if !result {
        Err(get_error())
    } else {
        Ok(())
    }
}

[kitt159]

In the original code, a reference to a temporary struct created by the to_ll function is created. This struct lives only inside of lambda, but the reference is then converted to a pointer, so the borrow checker can't catch it.
rect.into().map_or(ptr::null(), |r| &r.to_ll()),

I have created similar code in safe rust which shows the error exactly
https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=d2e86745124d8be508851184054d2885

[kitt159]

I believe there are additional issues in the code. This pattern appears frequently:

match src.into() {
    Some(ref rect) => &rect.to_ll(),
    None => ptr::null(),
}

The same problem occurs here as well. A temporary structure is created using to_ll, and a pointer is created to it. However, once the match block ends, the structure goes out of scope, causing the pointer to become invalid.