Fix http.FileServer short write

experimental/clashapi/server_fs.go

@@ -0,0 +1,18 @@
+package clashapi
+
+import "net/http"
+
+type Dir http.Dir
+
+func (d Dir) Open(name string) (http.File, error) {
+	file, err := http.Dir(d).Open(name)
+	if err != nil {
+		return nil, err
+	}
+	return &fileWrapper{file}, nil
+}
+
+// workaround for #2345 #2596
+type fileWrapper struct {
+	http.File
+}