Trait constraints issues with Eq for custom types

[mohammadfawaz]

Code:

script;

use core::ops::*;

impl<T> Option<T> {
    pub fn ok_or<E>(self, err: E) -> Result<T, E> {
        match self {
            Option::Some(v) => Result::Ok(v),
            Option::None => Result::Err(err),
        }
    }
}

enum Error {
    BoolError: bool,      
    U8Error: u8,      
}

impl Eq for Error {
    fn eq(self, other: Self) -> bool {
        match (self, other) {
            (Error::BoolError(val1), Error::BoolError(val2)) => val2 == val1,
            (Error::U8Error(val1), Error::U8Error(val2)) => val2 == val1,
            _ => false,
        }
    }
}

fn test_none_ok_or<T, E>(_val: T, default: E) where E: Eq {
    match Option::None::<T>().ok_or(default) {
        Result::Ok(_) => revert(0),
        Result::Err(e) => assert(default == e),
    }
}

fn main() {
    test_none_ok_or(true, Error::BoolError(true));
}

This compiles but reverts. When I change test_none_ok_or(true, Error::BoolError(true)); to test_none_ok_or(true, Error::BoolError(0)); for example, the test does not revert.

In test_none_ok_or, if I log default and e, I get the same value so the issue is with the comparison default == e which evaluates to false for some reason, even though Eq is implemented correctly. In fact, even if I change the implementation of Eq for Error to just be return true, the test still reverts 🤔

In fact, I don't think we're using the custom definition of Eq for Error at all! If I log some value in eq, I don't get any Log receipts back

[esdrubal]

Seems the same issue as #3351

When I disable inlining it is also using an empty implementation of eq.

pub fn eq_8(self !78: { u64, ( bool | u64 ) }, other !79: { u64, ( bool | u64 ) }) -> bool, !82 {
      entry(self: { u64, ( bool | u64 ) }, other: { u64, ( bool | u64 ) }):
      v0 = const bool undef
      ret bool v0
  }