xmpp-parsers: Fix jingle thumbnails wrt the XEP changes

Version 0.4.2 added a restriction on width and height to be in the
0..65535 range.  The media-type attribute has always been optional as
well.

parsers/ChangeLog

@@ -24,7 +24,9 @@ XXXX-YY-ZZ RELEASER <admin@example.com>
         nothing so far uses it for anything but this message.  We can always
         change it again once any other specification allows e.g. presences or
         iqs.
-      - Module `jingle_thumnails` renamed to `jingle_thumbnails`.
+      - Module `jingle_thumnails` has been renamed to `jingle_thumbnails`.  It
+        now respect the latest version of the XEP, with the width and height
+        being limited to 0..65535 and the media-type being optional (!475).
       - The bookmarks2 Conference `extensions` child is now an
         `Option<Extensions>` instead of a `Vec<Element>`, to distinguish
         between it being absent or empty (!472).

parsers/doap.xml

@@ -411,7 +411,7 @@
         <xmpp:SupportedXep>
             <xmpp:xep rdf:resource="https://xmpp.org/extensions/xep-0264.html"/>
             <xmpp:status>complete</xmpp:status>
-            <xmpp:version>0.4.1</xmpp:version>
+            <xmpp:version>0.4.2</xmpp:version>
             <xmpp:since>0.21.0</xmpp:since>
         </xmpp:SupportedXep>
     </implements>

parsers/src/jingle_thumbnails.rs

@@ -1,14 +1,15 @@
-//! Jingle thumbnails (XEP-0264)
+// Copyright (c) 2023 XMPP-RS contributors.
-
-// Copyright (c) 2023 XMPP-RS contributors.=
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, you can obtain one at http://mozilla.org/MPL/2.0/.
 
+//! Jingle thumbnails (XEP-0264)
+
 use xso::{AsXml, FromXml};
 
 use crate::ns;
+use core::num::NonZeroU16;
 
 /// A Jingle thumbnail.
 #[derive(FromXml, AsXml, PartialEq, Debug, Clone)]
@@ -19,23 +20,36 @@ pub struct Thumbnail {
     pub uri: String,
 
     /// The media type of the thumbnail.
-    #[xml(attribute = "media-type")]
+    #[xml(attribute(default, name = "media-type"))]
-    pub media_type: String,
+    pub media_type: Option<String>,
 
     /// The width of the thumbnail.
-    #[xml(attribute)]
+    #[xml(attribute(default))]
-    pub width: u32,
+    pub width: Option<NonZeroU16>,
 
     /// The height of the thumbnail.
-    #[xml(attribute)]
+    #[xml(attribute(default))]
-    pub height: u32,
+    pub height: Option<NonZeroU16>,
 }
 
 #[cfg(test)]
 mod tests {
     use crate::jingle_thumbnails::Thumbnail;
+    use core::num::NonZeroU16;
     use minidom::Element;
 
+    #[cfg(target_pointer_width = "32")]
+    #[test]
+    fn test_size() {
+        assert_size!(Thumbnail, 28);
+    }
+
+    #[cfg(target_pointer_width = "64")]
+    #[test]
+    fn test_size() {
+        assert_size!(Thumbnail, 56);
+    }
+
     #[test]
     fn test_simple_parse() {
         // Extracted from https://xmpp.org/extensions/xep-0264.html#example-1
@@ -53,8 +67,8 @@ mod tests {
             thumbnail.uri,
             "cid:sha1+ffd7c8d28e9c5e82afea41f97108c6b4@bob.xmpp.org"
         );
-        assert_eq!(thumbnail.media_type, "image/png");
+        assert_eq!(thumbnail.media_type.unwrap(), "image/png");
-        assert_eq!(thumbnail.width, 128);
+        assert_eq!(thumbnail.width, NonZeroU16::new(128));
-        assert_eq!(thumbnail.height, 96);
+        assert_eq!(thumbnail.height, NonZeroU16::new(96));
     }
 }