Suppress IOError when closing the temporary file used for capturing streams in Python 2.7.

Fix #2370

Author: nicoddemus

_pytest/capture.py

@@ -476,7 +476,7 @@ def done(self):
         os.dup2(targetfd_save, self.targetfd)
         os.close(targetfd_save)
         self.syscapture.done()
-        self.tmpfile.close()
+        _attempt_to_close_capture_file(self.tmpfile)
 
     def suspend(self):
         self.syscapture.suspend()
@@ -530,7 +530,7 @@ def snap(self):
     def done(self):
         setattr(sys, self.name, self._old)
         del self._old
-        self.tmpfile.close()
+        _attempt_to_close_capture_file(self.tmpfile)
 
     def suspend(self):
         setattr(sys, self.name, self._old)
@@ -681,3 +681,14 @@ def _reopen_stdio(f, mode):
     sys.__stdin__ = sys.stdin = _reopen_stdio(sys.stdin, 'rb')
     sys.__stdout__ = sys.stdout = _reopen_stdio(sys.stdout, 'wb')
     sys.__stderr__ = sys.stderr = _reopen_stdio(sys.stderr, 'wb')
+
+
+def _attempt_to_close_capture_file(f):
+    """Suppress IOError when closing the temporary file used for capturing streams in py27 (#2370)"""
+    if six.PY2:
+        try:
+            f.close()
+        except IOError:
+            pass
+    else:
+        f.close()

changelog/2370.bugfix.rst

@@ -0,0 +1 @@
+Suppress ``IOError`` when closing the temporary file used for capturing streams in Python 2.7.

testing/test_capture.py

@@ -1265,6 +1265,30 @@ def test_capattr():
     reprec.assertoutcome(passed=1)
 
 
+def test_crash_on_closing_tmpfile_py27(testdir):
+    testdir.makepyfile('''
+        from __future__ import print_function
+        import time
+        import threading
+        import sys
+
+        def spam():
+            f = sys.stderr
+            while True:
+                print('.', end='', file=f)
+
+        def test_silly():
+            t = threading.Thread(target=spam)
+            t.daemon = True
+            t.start()
+            time.sleep(0.5)
+
+    ''')
+    result = testdir.runpytest_subprocess()
+    assert result.ret == 0
+    assert 'IOError' not in result.stdout.str()
+
+
 def test_pickling_and_unpickling_encoded_file():
     # See https://bitbucket.org/pytest-dev/pytest/pull-request/194
     # pickle.loads() raises infinite recursion if