2.0.2

Fixed

• Parsing a track or route no longer takes quadratic time. Each closing <trkpt>/<rtept> copied every point parsed so far, so a 20,000-point recording took seconds and an 80,000-point one took minutes; parse time is now linear in file size.
• On Linux, parse(_:) and parse(contentsOf:) no longer reject documents larger than 10 MB with GPXError.malformedXML.
• Elements inside <extensions> whose names match GPX structure (metadata, wpt, trk, link, …) no longer overwrite the document's own metadata or add phantom waypoints, tracks, and links. They are kept as custom extension data like any other element.
• Structural elements are now only recognised under the parent the GPX schema gives them. An attribute-only <email> or <bounds> inside an unknown wrapper no longer closes that wrapper early (leaking the wrapper's later children into its parent), and containers nested in unknown wrappers are ignored along with the wrapper.
• Unknown children of a Garmin TrackPointExtension wrapper are no longer dropped — they land in GPXExtensions.custom like other unrecognised extension elements.
• Integer extension and waypoint values written as decimals (<hr>72.0</hr>, <sat>7.0</sat>) now parse instead of becoming nil. A known extension element whose text isn't a usable number is preserved in custom rather than discarded.
• Childless custom extension elements (<app:flag/>) are preserved with an empty value, so GPXCustomExtension values with an empty value now round-trip.
• NaN/inf are no longer accepted as numbers: in lat/lon they raise GPXError.invalidCoordinate, and in optional values (<ele>NaN</ele>, <bounds>) they become nil. Previously they parsed into documents the serializer then refused to write.
• An <extensions> block that carries no data now parses as nil rather than an empty GPXExtensions, matching what the serializer emits for it.
• An XML document whose root element is not <gpx> now raises GPXError.malformedXML instead of parsing "successfully" into an empty document.
• The serializer no longer emits malformed XML for text containing characters XML 1.0 cannot represent (most control characters) — they are dropped. Carriage returns, and tabs/newlines in attribute values, are written as character references so they survive a round trip instead of being normalized away by the reader.
• GPXDocument.namespaces entries that would make the root element malformed — a prefix the serializer already declares (xsi, or gpxtpx when Garmin fields are present), a prefix that isn't a valid XML name, or an empty URI — are skipped instead of written.
• Custom extension names containing characters an XML element name cannot hold are written with those characters replaced by _ instead of producing malformed XML.
• Garmin TrackPointExtension children are now written in the order the Garmin schema requires (atemp, wtemp, depth, hr, cad, speed, course, bearing).
• validate() now reports non-finite values in route-, track-, and segment-level extensions, which the serializer already rejected.
• simplified(tolerance:) no longer keeps every point of a straight line that crosses the antimeridian.
• Numbers that round to zero at 7 decimal places are written as 0, not -0.

Full changelog: CHANGELOG.md