Fix imagedata.registry.detect

imagetype/registry.go

@@ -149,7 +149,7 @@ func (r *registry) RegisterMagicBytes(typ Type, signature ...[]byte) {
 func (r *registry) Detect(re io.Reader) (Type, error) {
 	br := bufreader.New(io.LimitReader(re, maxDetectionLimit))
 
-	for _, fn := range globalRegistry.detectors {
+	for _, fn := range r.detectors {
 		br.Rewind()
 		if typ, err := fn(br); err == nil && typ != Unknown {
 			return typ, nil