bjoernager/rust
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make check a bit more clear

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Steven Fackler 2021-01-11 17:13:50 -05:00
parent a9ef7983a6
commit 5cb830397e
1 changed files with 3 additions and 2 deletions
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5
library/std/src/io/mod.rs
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@ -384,14 +384,15 @@ where
} }
} }
match r.read(&mut g.buf[g.len..]) { let buf = &mut g.buf[g.len..];
match r.read(buf) {
Ok(0) => return Ok(g.len - start_len), Ok(0) => return Ok(g.len - start_len),
Ok(n) => { Ok(n) => {
// We can't let g.len overflow which would result in the vec shrinking when the function returns. In // We can't let g.len overflow which would result in the vec shrinking when the function returns. In
// particular, that could break read_to_string if the shortened buffer doesn't end on a UTF-8 boundary. // particular, that could break read_to_string if the shortened buffer doesn't end on a UTF-8 boundary.
// The minimal check would just be a checked_add, but this assert is a bit more precise and should be // The minimal check would just be a checked_add, but this assert is a bit more precise and should be
// just about the same cost. // just about the same cost.
assert!(n <= g.buf.len() - g.len); assert!(n <= buf.len());
g.len += n; g.len += n;
} }
Err(ref e) if e.kind() == ErrorKind::Interrupted => {} Err(ref e) if e.kind() == ErrorKind::Interrupted => {}