Find assets using spec extension only if the extension is found in class extensions when class is given.
diff --git a/find.lisp b/find.lisp
index fc790e6..115b932 100644
--- a/find.lisp
+++ b/find.lisp
@@ -131,7 +131,9 @@
(extension-asset-classes ext))))))
(or (assets-matching class spec nil)
(with-asset-spec spec (name ext)
- (when ext
+ (when (if class
+ (find ext (asset-class-extensions class))
+ ext)
(assets-matching class name ext)))
assets)))