From baab73d521131a857ab6488bd2b40201f81f7bc8 Mon Sep 17 00:00:00 2001
From: Jan Tojnar <jtojnar@gmail.com>
Date: Wed, 20 Dec 2023 07:08:53 +0100
Subject: [PATCH] fix: Include type for OPML subscriptions

As per [OPML 2.0 specification]:

> Each sub-element of the body of the OPML document is a node of type rss or an outline element that contains nodes of type rss.

> Required attributes: type, text, xmlUrl.

[OPML 2.0 specification]: http://opml.org/spec2.opml#subscriptionLists
---
 internal/reader/opml/opml.go | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/internal/reader/opml/opml.go b/internal/reader/opml/opml.go
index 2f7147a0335..05aefd6453a 100644
--- a/internal/reader/opml/opml.go
+++ b/internal/reader/opml/opml.go
@@ -34,6 +34,23 @@ type opmlOutline struct {
 	Outlines opmlOutlineCollection `xml:"outline,omitempty"`
 }
 
+func (outline opmlOutline) MarshalXML() ([]byte, error) {
+	type opmlOutlineXml opmlOutline
+
+	outlineType := ""
+	if IsSubscription(outline) {
+		outlineType = "rss"
+	}
+
+	return xml.Marshal(struct {
+		opmlOutlineXml
+		Type string `xml:"type,attr,omitempty"`
+	}{
+		opmlOutlineXml: opmlOutlineXml(outline),
+		Type: outlineType,
+	})
+}
+
 func (o *opmlOutline) IsSubscription() bool {
 	return strings.TrimSpace(o.FeedURL) != ""
 }