std: Changing the meaning of the count to splitn

This commit is an implementation of [RFC 979][rfc] which changes the meaning of
the count parameter to the `splitn` function on strings and slices. The
parameter now means the number of items that are returned from the iterator, not
the number of splits that are made.

[rfc]: https://github.com/rust-lang/rfcs/pull/979

Closes #23911
[breaking-change]

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libstd/net/addr.rs b/src/libstd/net/addr.rs
index c45230e91ba..886f252fb19 100644
--- a/src/libstd/net/addr.rs
+++ b/src/libstd/net/addr.rs
@@ -441,7 +441,7 @@ impl ToSocketAddrs for str {
         }
 
         // split the string by ':' and convert the second part to u16
-        let mut parts_iter = self.rsplitn(1, ':');
+        let mut parts_iter = self.rsplitn(2, ':');
         let port_str = try_opt!(parts_iter.next(), "invalid socket address");
         let host = try_opt!(parts_iter.next(), "invalid socket address");
         let port: u16 = try_opt!(port_str.parse().ok(), "invalid port value");