green.subprocess: keep CalledProcessError identity

#413

eventlet/green/subprocess.py

@@ -133,3 +133,9 @@ def patched_function(function):
     __patched__.append('check_output')
     check_output = patched_function(subprocess_orig.check_output)
 del patched_function
+
+# Keep exceptions identity.
+# https://github.com/eventlet/eventlet/issues/413
+subprocess_imported = sys.modules['subprocess']
+CalledProcessError = subprocess_imported.CalledProcessError
+del subprocess_imported

tests/isolated/subprocess_exception_identity.py

@@ -0,0 +1,12 @@
+__test__ = False
+
+if __name__ == '__main__':
+    import subprocess as original
+    from eventlet.green import subprocess as green
+
+    cases = (
+        'CalledProcessError',
+    )
+    for c in cases:
+        assert getattr(green, c) is getattr(original, c), c
+    print('pass')

tests/subprocess_test.py

@@ -93,3 +93,9 @@ def test_check_call_without_timeout_works():
         stdout=subprocess.PIPE,
         stderr=subprocess.PIPE,
     )
+
+
+def test_exception_identity():
+    # https://github.com/eventlet/eventlet/issues/413
+    # green module must keep exceptions classes as stdlib version
+    tests.run_isolated('subprocess_exception_identity.py')