Merge with cpython.

1 files changed, 4 insertions, 2 deletions

diff --git a/Lib/tarfile.py b/Lib/tarfile.py
index 63c7554af2..3d52a81b9e 100644
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -1804,11 +1804,13 @@ class TarFile(object):
             fileobj = gzip.GzipFile(name, mode + "b", compresslevel, fileobj)
             t = cls.taropen(name, mode, fileobj, **kwargs)
         except IOError:
-            if not extfileobj:
+            if not extfileobj and fileobj is not None:
                 fileobj.close()
+            if fileobj is None:
+                raise
             raise ReadError("not a gzip file")
         except:
-            if not extfileobj:
+            if not extfileobj and fileobj is not None:
                 fileobj.close()
             raise
         t._extfileobj = extfileobj