Fix issue 90 - empty manifest config support on Windows (#91)

* Fix issue 90 - empty manifest config support on Windows

Signed-off-by: Sunny Carter <sunny.carter@metaswitch.com>

Author: sunnycarter

CHANGELOG.md

@@ -14,6 +14,7 @@ and **Merged pull requests**. Critical items to know are:
 The versions coincide with releases on pip. Only major versions will be released as tags on Github.
 
 ## [0.0.x](https://github.com/oras-project/oras-py/tree/main) (0.0.x)
+  - patch fix for empty manifest config on Windows, closes issue [90](https://github.com/oras-project/oras-py/issues/90) (0.1.18)
   - patch fix to correct session url pattern, closes issue [78](https://github.com/oras-project/oras-py/issues/78) (0.1.17)
   - add support for tag deletion and retry decorators (0.1.16)
  - bugfix that pagination sets upper limit of 10K (0.1.15)

oras/oci.py

@@ -128,7 +128,7 @@ def ManifestConfig(
     """
     # Create an empty config if we don't have one
     if not path or not os.path.exists(path):
-        path = "/dev/null"
+        path = os.devnull
         conf = {
             "mediaType": media_type or oras.defaults.unknown_config_media_type,
             "size": 0,

oras/provider.py

@@ -430,7 +430,7 @@ def download_blob(
         # Allow an empty layer to fail and return /dev/null
         except Exception as e:
             if digest == oras.defaults.blank_hash:
-                return "/dev/null"
+                return os.devnull
             raise e
         return outfile
 

oras/version.py

@@ -2,7 +2,7 @@
 __copyright__ = "Copyright The ORAS Authors."
 __license__ = "Apache-2.0"
 
-__version__ = "0.1.17"
+__version__ = "0.1.18"
 AUTHOR = "Vanessa Sochat"
 EMAIL = "vsoch@users.noreply.github.com"
 NAME = "oras"