green.subprocess: keep CalledProcessError identity

https://github.com/eventlet/eventlet/issues/413

eventlet/green/subprocess.py

@@ -133,3 +133,7 @@ if hasattr(subprocess_orig, 'check_output'):
     __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
+CalledProcessError = subprocess_orig.CalledProcessError

tests/subprocess_test.py

@@ -93,3 +93,13 @@ 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
+    cases = (
+        'CalledProcessError',
+    )
+    for c in cases:
+        assert getattr(subprocess, c) is getattr(original_subprocess, c), c