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vec: Fix size_hint() of reverse iterators #7565

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Merged
merged 1 commit into from
Jul 4, 2013
Merged

vec: Fix size_hint() of reverse iterators #7565

merged 1 commit into from
Jul 4, 2013

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Blei
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@Blei Blei commented Jul 3, 2013

Fixes #7558

@alexcrichton
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There's also the separate problem of why does this fix the problem? Rust isn't a language that should segfault because of a bug in an implementation. Does this happen because a negative int is casted to an unsigned int?

@bluss
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bluss commented Jul 4, 2013

@alexcrichton this testcase has a similar crash, no overflow checking in ~[]::reserve.

fn main() {
    let mut v = ~[];
    v.reserve(-1);
    v.push(1);
    v.push(2);
}
// *** glibc detected *** ./crash~: free(): invalid next size (fast): 0x00000000022e9040 ***

@alexcrichton
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Yes, but I meant that this bug should be fixed as well as that one: #7578

thestinger added a commit that referenced this pull request Jul 4, 2013
@thestinger
Merge pull request #7565 from Blei/fix-rev-size-hint
dd4f6bb 
vec: Fix size_hint() of reverse iterators
@thestinger thestinger merged commit dd4f6bb into rust-lang:master Jul 4, 2013
@Blei Blei deleted the fix-rev-size-hint branch July 4, 2013 09:18
flip1995 pushed a commit to flip1995/rust that referenced this pull request Sep 3, 2021
@bors
Auto merge of rust-lang#7565 - Jarcho:manual_split_once, r=llogiq
1fc1aee 
New lint `manual_split_once`

This is a WIP because it still needs to recognize more patterns. Currently handles:

```rust
s.splitn(2, ' ').next();
s.splitn(2, ' ').nth(0)
s.splitn(2, ' ').nth(1);
s.splitn(2, ' ').skip(0).next();
s.splitn(2, ' ').skip(1).next();
s.splitn(2, ' ').next_tuple(); // from itertools

// as well as `unwrap()` and `?` forms
```

Still to do:

```rust
let mut iter = s.splitn(2, ' ');
(iter.next().unwrap(), iter.next()?)

let mut iter = s.splitn(2, ' ');
let key = iter.next().unwrap();
let value = iter.next()?;
```

Suggestions on other patterns to check for would be useful. I've done a search on github for uses of `splitn`. Still have yet to actually look through the results.

There's also the question of whether the lint shouold trigger on all uses of `splitn` with two values, or only on recognized usages. The former could have false positives where it couldn't be replaced, but I'm not sure how common that would be.

changelog: Add lint `manual_split_once`
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Successfully merging this pull request may close these issues.

vec.rev_iter().collect() causes memory corruption
5 participants
@Blei @alexcrichton @bluss @bors @thestinger