Not able to upload a compressed S3 file using close() (#838)

* Call inner close() call during outer close() call in FileLikeProxy class

* Return close() result in FileLikeProxy class

smart_open/tests/test_s3.py

@@ -634,6 +634,43 @@ def test_writebuffer(self):
 
             assert actual == contents
 
+    def test_write_gz_using_context_manager(self):
+        """Does s3 multipart upload create a compressed file using context manager?"""
+        contents = b'get ready for a surprise'
+        with smart_open.open(
+                f's3://{BUCKET_NAME}/{WRITE_KEY_NAME}.gz',
+                mode="wb",
+                transport_params={
+                    "multipart_upload": True,
+                    "min_part_size": 10,
+                }
+        ) as fout:
+            fout.write(contents)
+
+        with smart_open.open(f's3://{BUCKET_NAME}/{WRITE_KEY_NAME}.gz', 'rb') as fin:
+            actual = fin.read()
+
+        assert actual == contents
+
+    def test_write_gz_not_using_context_manager(self):
+        """Does s3 multipart upload create a compressed file not using context manager but close()?"""
+        contents = b'get ready for a surprise'
+        fout = smart_open.open(
+            f's3://{BUCKET_NAME}/{WRITE_KEY_NAME}.gz',
+            mode="wb",
+            transport_params={
+                "multipart_upload": True,
+                "min_part_size": 10,
+            }
+        )
+        fout.write(contents)
+        fout.close()
+
+        with smart_open.open(f's3://{BUCKET_NAME}/{WRITE_KEY_NAME}.gz', 'rb') as fin:
+            actual = fin.read()
+
+        assert actual == contents
+
     def test_write_gz_with_error(self):
         """Does s3 multipart upload abort for a failed compressed file upload?"""
         with self.assertRaises(ValueError):

smart_open/utils.py

@@ -223,3 +223,10 @@ def __exit__(self, *args, **kwargs):
 
     def __next__(self):
         return self.__wrapped__.__next__()
+
+    def close(self):
+        try:
+            return self.__wrapped__.close()
+        finally:
+            if self.__inner != self.__wrapped__:  # Don't close again if inner and wrapped are the same
+                self.__inner.close()