Merge pull request #1467 from abderrahim/artifact-meta

_artifact.py: don't consider an artifact cached if metadata is missing
diff --git a/src/buildstream/_artifact.py b/src/buildstream/_artifact.py
index da1e03a..28e2f59 100644
--- a/src/buildstream/_artifact.py
+++ b/src/buildstream/_artifact.py
@@ -574,7 +574,7 @@
 
         # Check whether public data and logs are available
         logfile_digests = [logfile.digest for logfile in artifact.logs]
-        digests = [artifact.public_data] + logfile_digests
+        digests = [artifact.low_diversity_meta, artifact.high_diversity_meta, artifact.public_data] + logfile_digests
         if not self._cas.contains_files(digests):
             self._cached = False
             return False