rollup merge of #19869: sfackler/free-stdin

r? @aturon

1 files changed, 7 insertions, 0 deletions

diff --git a/src/libstd/io/stdio.rs b/src/libstd/io/stdio.rs
index c180476efb8..844814fbfdd 100644
--- a/src/libstd/io/stdio.rs
+++ b/src/libstd/io/stdio.rs
@@ -41,6 +41,7 @@ use option::Option;
 use option::Option::{Some, None};
 use ops::{Deref, DerefMut, FnOnce};
 use result::Result::{Ok, Err};
+use rt;
 use rustrt;
 use rustrt::local::Local;
 use rustrt::task::Task;
@@ -224,6 +225,12 @@ pub fn stdin() -> StdinReader {
                 inner: Arc::new(Mutex::new(stdin))
             };
             STDIN = mem::transmute(box stdin);
+
+            // Make sure to free it at exit
+            rt::at_exit(|| {
+                mem::transmute::<_, Box<StdinReader>>(STDIN);
+                STDIN = 0 as *const _;
+            });
         });
 
         (*STDIN).clone()