From 032bffa5b8ae6c3977884c4e10fd6ab6a5dc5ef6 Mon Sep 17 00:00:00 2001
From: "Stephen M. Coakley" <me@stephencoakley.com>
Date: Fri, 7 Oct 2016 17:45:04 -0500
Subject: [PATCH] Unlock guard before overflow panic

---
 src/libstd/thread/mod.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/libstd/thread/mod.rs b/src/libstd/thread/mod.rs
index c8b6046bb8d6..98feea96f8c4 100644
--- a/src/libstd/thread/mod.rs
+++ b/src/libstd/thread/mod.rs
@@ -550,6 +550,7 @@ impl ThreadId {
             // If we somehow use up all our bits, panic so that we're not
             // covering up subtle bugs of IDs being reused.
             if COUNTER == ::u64::MAX {
+                GUARD.unlock();
                 panic!("failed to generate unique thread ID: bitspace exhausted");
             }