From a3477060f1974ef1413e5a2108fbdf60d4299be0 Mon Sep 17 00:00:00 2001
From: Casper da Costa-Luis <tqdm@caspersci.uk.to>
Date: Tue, 27 Aug 2019 14:49:53 +0100
Subject: [PATCH] potential thread safety fix

- related: #548
---
 tqdm/std.py | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/tqdm/std.py b/tqdm/std.py
index 26baea04f..e93590ff2 100644
--- a/tqdm/std.py
+++ b/tqdm/std.py
@@ -1022,9 +1022,13 @@ def __len__(self):
     def __enter__(self):
         return self
 
-    def __exit__(self, *exc):
-        self.close()
-        return False
+    def __exit__(self, exc_type, exc_value, traceback):
+        try:
+            self.close()
+        except AttributeError:
+            # maybe eager thread cleanup upon external error
+            if exc_type is None:
+                raise
 
     def __del__(self):
         self.close()