BUG: compiler doesn't detect method-chain lifetime breach?

[phildawes]

The following code results in corrupt output: (Ubuntu 12.04 LTS, rust master pulled 25th Feb)

let arr : ~[&str] = std::os::args()[1].split_str("::").collect();
std::io::println("first " + arr[0]);
std::io::println("first again " + arr[0]);

$ rustc isolate_issue.rs
$ ./isolate_issue "foo::bar"
first fir
first again

Ashish Myles noted that an earlier version of rust failed to compile this code, giving an error about the reference to the return value of std::os::args() not being valid for the duration of its use.

https://mail.mozilla.org/pipermail/rust-dev/2014-February/008796.html

Pulling 'args' into a separate local variable works:

let args = std::os::args();
let arr : ~[&str] = args[1].split_str("::").collect();
std::io::println("first " + arr[0]);
std::io::println("first again " + arr[0]);

$ ./isolate_issue "foo::bar"
first foo
first again foo

[lilyball]

As @flaper87 pointed out, this may be related to #12223.

[alexcrichton]

I think @kballard is right, closing as a dupe of #12223

[flaper87]

I do think it is a duplicate so, I'll close this bug as a duplicate of #12223