patcher: built-in open() did not accept kwargs

#683

eventlet/green/builtin.py

@@ -38,9 +38,9 @@ def __init__(self, *args, **kwargs):
 __opening = False
 
 
-def open(*args):
+def open(*args, **kwargs):
     global __opening
-    result = __original_open(*args)
+    result = __original_open(*args, **kwargs)
     if not __opening:
         # This is incredibly ugly. 'open' is used under the hood by
         # the import process. So, ensure we don't wind up in an

tests/isolated/patcher_open_kwargs.py

@@ -0,0 +1,10 @@
+__test__ = False
+
+if __name__ == "__main__":
+    import eventlet
+    eventlet.monkey_patch(builtins=True, os=True)
+
+    with open(__file__, mode="rt", buffering=16):
+        pass
+
+    print("pass")

tests/patcher_test.py

@@ -523,3 +523,7 @@ def test_fork_after_monkey_patch():
 
 def test_builtin():
     tests.run_isolated('patcher_builtin.py')
+
+
+def test_open_kwargs():
+    tests.run_isolated("patcher_open_kwargs.py")