bpo-38971: Open file in codecs.open() closes if exception raised. (GH-17666)

Open issue in the BPO indicated a desire to make the implementation of
codecs.open() at parity with io.open(), which implements a try/except to
assure file stream gets closed before an exception is raised.

1 files changed, 10 insertions, 5 deletions

diff --git a/Lib/codecs.py b/Lib/codecs.py
index 21c45a7..7f23e97 100644
--- a/Lib/codecs.py
+++ b/Lib/codecs.py
@@ -905,11 +905,16 @@ def open(filename, mode='r', encoding=None, errors='strict', buffering=-1):
     file = builtins.open(filename, mode, buffering)
     if encoding is None:
         return file
-    info = lookup(encoding)
-    srw = StreamReaderWriter(file, info.streamreader, info.streamwriter, errors)
-    # Add attributes to simplify introspection
-    srw.encoding = encoding
-    return srw
+
+    try:
+        info = lookup(encoding)
+        srw = StreamReaderWriter(file, info.streamreader, info.streamwriter, errors)
+        # Add attributes to simplify introspection
+        srw.encoding = encoding
+        return srw
+    except:
+        file.close()
+        raise
 
 def EncodedFile(file, data_encoding, file_encoding=None, errors='strict'):