From 55c53080dbbd2d81ebd0c3d98bb0e0831d6064d0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pablo=20Correa=20G=C3=B3mez?= <ablocorrea@hotmail.com>
Date: Sat, 15 Jan 2022 22:51:10 +0100
Subject: [PATCH 3/5] appstream: implement parsing media_baseurl

This property was not documented for XML data until quite
recently: https://github.com/ximion/appstream/pull/371

However, remote icons and screenshots generated with appstream-generator
only contain urls relative to media_baseurl property. Fix all relative uris
prepending the corresponding media_baseurl for those objects to be downloadable.
---
 lib/gs-appstream.c                 | 19 +++++++++
 lib/gs-appstream.h                 |  2 +
 plugins/core/gs-plugin-appstream.c | 64 ++++++++++++++++++++++++++++++
 3 files changed, 85 insertions(+)

diff --git a/lib/gs-appstream.c b/lib/gs-appstream.c
index df91dd0f..8e157595 100644
--- a/lib/gs-appstream.c
+++ b/lib/gs-appstream.c
@@ -1824,3 +1824,22 @@ gs_appstream_component_add_extra_info (XbBuilderNode *component)
 		break;
 	}
 }
+
+/* Resolve any media URIs which are actually relative
+ * paths against the media_baseurl property */
+void
+gs_appstream_component_fix_url (XbBuilderNode *component, const gchar *baseurl)
+{
+	const gchar *text = xb_builder_node_get_text (component);
+	g_autofree gchar *url = NULL;
+
+	if (text == NULL)
+		return;
+
+	if (g_str_has_prefix (text, "http:") ||
+	    g_str_has_prefix (text, "https:"))
+		return;
+
+	url = g_strconcat (baseurl, "/", text, NULL);
+	xb_builder_node_set_text (component, url , -1);
+}
diff --git a/lib/gs-appstream.h b/lib/gs-appstream.h
index 5bddf913..fbc68a1a 100644
--- a/lib/gs-appstream.h
+++ b/lib/gs-appstream.h
@@ -72,5 +72,7 @@ void		 gs_appstream_component_add_icon	(XbBuilderNode	*component,
 							 const gchar	*str);
 void		 gs_appstream_component_add_provide	(XbBuilderNode	*component,
 							 const gchar	*str);
+void		 gs_appstream_component_fix_url		(XbBuilderNode  *component,
+							 const gchar    *baseurl);
 
 G_END_DECLS
diff --git a/plugins/core/gs-plugin-appstream.c b/plugins/core/gs-plugin-appstream.c
index 5d61c5b6..950316f2 100644
--- a/plugins/core/gs-plugin-appstream.c
+++ b/plugins/core/gs-plugin-appstream.c
@@ -133,6 +133,60 @@ gs_plugin_appstream_add_origin_keyword_cb (XbBuilderFixup *self,
 	return TRUE;
 }
 
+static void
+gs_plugin_appstream_media_baseurl_free (gpointer user_data)
+{
+	g_string_free ((GString *) user_data, TRUE);
+}
+
+static gboolean
+gs_plugin_appstream_media_baseurl_cb (XbBuilderFixup *self,
+				      XbBuilderNode *bn,
+				      gpointer user_data,
+				      GError **error)
+{
+	GString *baseurl = user_data;
+	if (g_strcmp0 (xb_builder_node_get_element (bn), "components") == 0) {
+		const gchar *url = xb_builder_node_get_attr (bn, "media_baseurl");
+		if (url == NULL) {
+			g_string_truncate (baseurl, 0);
+			return TRUE;
+		}
+		g_string_assign (baseurl, url);
+		return TRUE;
+	}
+
+	if (baseurl->len == 0)
+		return TRUE;
+
+	if (g_strcmp0 (xb_builder_node_get_element (bn), "icon") == 0) {
+		const gchar *type = xb_builder_node_get_attr (bn, "type");
+		if (g_strcmp0 (type, "remote") != 0)
+			return TRUE;
+		gs_appstream_component_fix_url (bn, baseurl->str);
+	} else if (g_strcmp0 (xb_builder_node_get_element (bn), "screenshots") == 0) {
+		GPtrArray *screenshots = xb_builder_node_get_children (bn);
+		for (guint i = 0; i < screenshots->len; i++) {
+			XbBuilderNode *screenshot = g_ptr_array_index (screenshots, i);
+			GPtrArray *children = NULL;
+			/* Type-check for security */
+			if (g_strcmp0 (xb_builder_node_get_element (screenshot), "screenshot") != 0) {
+				continue;
+			}
+			children = xb_builder_node_get_children (screenshot);
+			for (guint j = 0; j < children->len; j++) {
+				XbBuilderNode *child = g_ptr_array_index (children, j);
+				const gchar *element = xb_builder_node_get_element (child);
+				if (g_strcmp0 (element, "image") != 0 &&
+				    g_strcmp0 (element, "video") != 0)
+					continue;
+				gs_appstream_component_fix_url (child, baseurl->str);
+			}
+		}
+	}
+	return TRUE;
+}
+
 static gboolean
 gs_plugin_appstream_load_appdata_fn (GsPlugin *plugin,
 				     XbBuilder *builder,
@@ -398,6 +452,8 @@ gs_plugin_appstream_load_appstream_fn (GsPlugin *plugin,
 #if LIBXMLB_CHECK_VERSION(0,3,1)
 	g_autoptr(XbBuilderFixup) fixup4 = NULL;
 #endif
+	g_autoptr(XbBuilderFixup) fixup5 = NULL;
+	GString *media_baseurl = g_string_new (NULL);
 	g_autoptr(XbBuilderSource) source = xb_builder_source_new ();
 
 	/* add support for DEP-11 files */
@@ -453,6 +509,14 @@ gs_plugin_appstream_load_appstream_fn (GsPlugin *plugin,
 	xb_builder_source_add_fixup (source, fixup4);
 #endif
 
+	/* prepend media_baseurl to remote relative URLs */
+	fixup5 = xb_builder_fixup_new ("MediaBaseUrl",
+				       gs_plugin_appstream_media_baseurl_cb,
+				       media_baseurl,
+				       gs_plugin_appstream_media_baseurl_free);
+	xb_builder_fixup_set_max_depth (fixup5, 3);
+	xb_builder_source_add_fixup (source, fixup5);
+
 	/* success */
 	xb_builder_import_source (builder, source);
 	return TRUE;
-- 
2.25.1