add inline comment to core/user

core/user.go

@@ -515,6 +515,9 @@ func getUserFrequentTags(r *http.Request, ids string, category UserWorkCategory)
 	}
 
 	// Return early if there are no IDs
+	//
+	// NOTE: theoretically, this check should never be reached as fetchUserWorks doesn't call
+	// getUserFrequentTags when len(tagsIDs) == 0, instead returning an empty []FrequentTag
 	if ids == "" {
 		return tags, nil
 	}