fix: check if configPath is empty before writing to Annotations (#509)

Signed-off-by: wangxiaoxuan273 <[email protected]>

cmd/oras/pull.go

@@ -111,21 +111,22 @@ func runPull(opts pullOptions) error {
 		}
 		var ret []ocispec.Descriptor
 		// Iterate all the successors to
-		// 1) Add name annotation if configPath is not empty
-		// 2) Skip fetching unamed leaf nodes
+		// 1) Add name annotation to config if configPath is not empty
+		// 2) Skip fetching unnamed leaf nodes
 		for i, s := range successors {
 			// Save the config when:
 			// 1) MediaType matches, or
 			// 2) MediaType not specified and current node is config.
 			// Note: For a manifest, the 0th indexed element is always a
 			// manifest config.
-			if s.MediaType == configMediaType || (configMediaType == "" && i == 0 && isManifestMediaType(desc.MediaType)) {
+			if (s.MediaType == configMediaType || (configMediaType == "" && i == 0 && isManifestMediaType(desc.MediaType))) && configPath != "" {
 				// Add annotation for manifest config
 				if s.Annotations == nil {
 					s.Annotations = make(map[string]string)
 				}
 				s.Annotations[ocispec.AnnotationTitle] = configPath
-			} else if s.Annotations[ocispec.AnnotationTitle] == "" {
+			}
+			if s.Annotations[ocispec.AnnotationTitle] == "" {
 				ss, err := content.Successors(ctx, fetcher, s)
 				if err != nil {
 					return nil, err