echo: fix wrapping behavior of octal sequences
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tertsdiepraam
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src/uu/echo/src/echo.rs
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| for _ in 1..max_digits { | ||
| match input.peek().and_then(|c| c.to_digit(base as u32)) { | ||
| Some(n) => ret = ret.wrapping_mul(base).wrapping_add(n as u8), | ||
| None => break, | ||
| } | ||
| input.next(); |
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even though Option isn't marked #[must_use], it might be nice to do let _ = input.next()
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though maybe clippy complains because it's technically not necessary, I always like it cause it's clear we don't care (instead of the unwrap above, which I guess could be the same let _ =
tertsdiepraam
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I'm not sure whether this is outside the scope of this PR: GNU With your solution I get: |
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Yeah sure, I've added it. |
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GNU testsuite comparison: |
sylvestre
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cakebaker
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GNU testsuite comparison: |
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Funny behaviour in GNU:
Even though the octal code for
Ais\0101. The reason that happens is because 3 octal digits is equivalent to a 9 bit integer.This is possibly a bug in GNU that nobody has fixed in 31 years or they just chose to ignore it since it is fairly minor. I was investigating this with @jdonszelmann and we found that GNU and the built-in
echofor zsh and fish both also have this wrapping behaviour. Though it's not really a problem because it is all done usingunsignedintegers. In this PR, I've made sure to use thewrapping_*methods for arithmetic to further avoid any problems.Some other utilities might need to be checked too. For instance
printf:I noticed this while I was refactoring
print_escaped, which is why that function is changed too.