Ensure labels is not nil in differ

crosbymichael · crosbymichael · commit b2d260c4f4d9 · 2019-06-14T15:46:14.000Z
Signed-off-by: Michael Crosby &lt;crosbymichael@gmail.com&gt;
diff --git a/diff/walking/differ.go b/diff/walking/differ.go
@@ -150,7 +150,9 @@ func (s *walkingDiff) Compare(ctx context.Context, lower, upper []mount.Mount, o
 			if err != nil {
 				return errors.Wrap(err, "failed to get info from content store")
 			}
-
+			if info.Labels == nil {
+				info.Labels = make(map[string]string)
+			}
 			// Set uncompressed label if digest already existed without label
 			if _, ok := info.Labels[uncompressed]; !ok {
 				info.Labels[uncompressed] = config.Labels[uncompressed]
