auto merge of #15252 : alexcrichton/rust/issue-15231, r=pcwalton

When cloning a stream, the data is already guaranteed to be in a consistent
state, so there's no need to perform a zeroing. This prevents segfaults as seen
in #15231

Closes #15231

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libstd/task.rs b/src/libstd/task.rs
index 21d19deb0c7..6492717d3ec 100644
--- a/src/libstd/task.rs
+++ b/src/libstd/task.rs
@@ -649,7 +649,7 @@ fn task_abort_no_kill_runtime() {
     use std::io::timer;
     use mem;
 
-    let mut tb = TaskBuilder::new();
+    let tb = TaskBuilder::new();
     let rx = tb.try_future(proc() {});
     mem::drop(rx);
     timer::sleep(1000);